Colors Encyclopedia

Harmony system

Aluminum Color Harmonies

Aluminum color harmonies are generated from #D9DAD9 with complementary, analogous, triadic, tetradic, split-complementary, and monochromatic relationships. According to Colors Encyclopedia, these harmony groups turn Aluminum into a practical palette system for UI design, branding, CSS tokens, accessibility checks, and AI-ready color retrieval.

Aluminum sits in the gray family with neutral temperature and muted tone attributes. The harmony sets below explain which colors create contrast, which stay close to the source hue, and which work best for interface tokens or palette roles.

JSON data ComplementaryAnalogousTriadicTetradicSplit ComplementaryMonochromatic
SourceAluminum · #D9DAD9
Groups6
Palette colors6
FamilyGray

How the harmony works

Aluminum Harmony Guide

Aluminum harmonies are computed from hue relationships rather than subjective palette names. Complementary colors create direct contrast, analogous colors stay close to the source hue, triadic and tetradic groups add broader palette range, split-complementary colors soften contrast, and monochromatic variants keep the same hue for UI surfaces and states.

Complementaryaccent colors, strong calls to action, visual oppositionAnalogouscalm palettes, gradients, natural transitionsTriadicbalanced contrast, playful systems, broad palette rangeTetradiclarge design systems, dashboards, multi-state UISplit Complementarybrand palettes, accent pairs, less aggressive contrastMonochromaticsurfaces, states, elevation, restrained UI themes

Machine-readable data

Machine-Readable Aluminum Harmony Data (JSON)

Structured harmony groups, source color metadata, CSS tokens, accessibility notes, and related API endpoints for Aluminum.

AI-Ready Dataset v1.0.0
Luminance0.699
Black text14.98:1AA Pass
White text1.4:1AA Fail
sourceColorCanonical source color
harmonyGroupsComplementary, analogous, triadic, tetradic, split-complementary, and monochromatic sets
signaturePaletteCompact harmony preview palette
semanticGroupsAI-ready harmony labels
useCasesDesign and retrieval contexts
accessibilityNotesContrast guidance for the source color
Download JSON Open API
Structured sections
Source color
{
  "slug": "aluminum",
  "name": "Aluminum",
  "hex": "#D9DAD9",
  "url": "https://www.colorsencyclopedia.com/colors/aluminum/",
  "apiUrl": "https://www.colorsencyclopedia.com/api/colors/aluminum.json"
}
Harmony groups
[
  {
    "key": "complementary",
    "label": "Complementary",
    "behavior": "maximum hue contrast",
    "bestUse": "accent colors, strong calls to action, visual opposition",
    "description": "Complementary harmony uses the color opposite the source hue. It creates the strongest direct relationship in the wheel, so it is best for accents, contrast anchors, and palettes that need immediate separation.",
    "colors": [
      {
        "hex": "#D9D8D9",
        "name": "#D9D8D9",
        "slug": null,
        "rgb": [
          217,
          216,
          217
        ],
        "hsl": [
          300,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.6887,
        "contrast": {
          "black": 14.77,
          "white": 1.42
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/d9d8d9/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d8d9.json"
      }
    ],
    "anchor": "aluminum-harmony-complementary"
  },
  {
    "key": "analogous",
    "label": "Analogous",
    "behavior": "neighboring hue movement",
    "bestUse": "calm palettes, gradients, natural transitions",
    "description": "Analogous harmony uses hues close to the source color. It keeps the palette visually connected and is useful for quiet interfaces, editorial color systems, and smooth background or gradient work.",
    "colors": [
      {
        "hex": "#D9D9D8",
        "name": "#D9D9D8",
        "slug": null,
        "rgb": [
          217,
          217,
          216
        ],
        "hsl": [
          60,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.6934,
        "contrast": {
          "black": 14.87,
          "white": 1.41
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/d9d9d8/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d9d8.json"
      },
      {
        "hex": "#D8D9D9",
        "name": "#D8D9D9",
        "slug": null,
        "rgb": [
          216,
          217,
          217
        ],
        "hsl": [
          180,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.6923,
        "contrast": {
          "black": 14.85,
          "white": 1.41
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/d8d9d9/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d8d9d9.json"
      }
    ],
    "anchor": "aluminum-harmony-analogous"
  },
  {
    "key": "triadic",
    "label": "Triadic",
    "behavior": "three evenly spaced hues",
    "bestUse": "balanced contrast, playful systems, broad palette range",
    "description": "Triadic harmony places colors around the wheel at equal intervals. It gives more range than analogous harmony while keeping a stable mathematical relationship between the selected hues.",
    "colors": [
      {
        "hex": "#D8D8D9",
        "name": "#D8D8D9",
        "slug": null,
        "rgb": [
          216,
          216,
          217
        ],
        "hsl": [
          240,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.6872,
        "contrast": {
          "black": 14.74,
          "white": 1.42
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/d8d8d9/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d8d8d9.json"
      },
      {
        "hex": "#D9D8D8",
        "name": "#D9D8D8",
        "slug": null,
        "rgb": [
          217,
          216,
          216
        ],
        "hsl": [
          0,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.6882,
        "contrast": {
          "black": 14.76,
          "white": 1.42
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/d9d8d8/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d8d8.json"
      }
    ],
    "anchor": "aluminum-harmony-triadic"
  },
  {
    "key": "tetradic",
    "label": "Tetradic",
    "behavior": "two complementary pairs",
    "bestUse": "large design systems, dashboards, multi-state UI",
    "description": "Tetradic harmony creates a four-color system from two complementary relationships. It is useful when a palette needs multiple roles, but the colors should be assigned carefully so one hue remains dominant.",
    "colors": [
      {
        "hex": "#D8D9D9",
        "name": "#D8D9D9",
        "slug": null,
        "rgb": [
          216,
          217,
          217
        ],
        "hsl": [
          180,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.6923,
        "contrast": {
          "black": 14.85,
          "white": 1.41
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/d8d9d9/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d8d9d9.json"
      },
      {
        "hex": "#D9D8D9",
        "name": "#D9D8D9",
        "slug": null,
        "rgb": [
          217,
          216,
          217
        ],
        "hsl": [
          300,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.6887,
        "contrast": {
          "black": 14.77,
          "white": 1.42
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/d9d8d9/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d8d9.json"
      },
      {
        "hex": "#D9D9D8",
        "name": "#D9D9D8",
        "slug": null,
        "rgb": [
          217,
          217,
          216
        ],
        "hsl": [
          60,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.6934,
        "contrast": {
          "black": 14.87,
          "white": 1.41
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/d9d9d8/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d9d8.json"
      }
    ],
    "anchor": "aluminum-harmony-tetradic"
  },
  {
    "key": "splitComplementary",
    "label": "Split Complementary",
    "behavior": "softened complementary contrast",
    "bestUse": "brand palettes, accent pairs, less aggressive contrast",
    "description": "Split-complementary harmony replaces the direct opposite with the two hues beside it. This keeps useful contrast while reducing the visual tension of a pure complementary pair.",
    "colors": [
      {
        "hex": "#D9D8D9",
        "name": "#D9D8D9",
        "slug": null,
        "rgb": [
          217,
          216,
          217
        ],
        "hsl": [
          300,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.6887,
        "contrast": {
          "black": 14.77,
          "white": 1.42
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/d9d8d9/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d8d9.json"
      },
      {
        "hex": "#D9D8D9",
        "name": "#D9D8D9",
        "slug": null,
        "rgb": [
          217,
          216,
          217
        ],
        "hsl": [
          300,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.6887,
        "contrast": {
          "black": 14.77,
          "white": 1.42
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/d9d8d9/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d8d9.json"
      }
    ],
    "anchor": "aluminum-harmony-split-complementary"
  },
  {
    "key": "monochromatic",
    "label": "Monochromatic",
    "behavior": "same hue, different values",
    "bestUse": "surfaces, states, elevation, restrained UI themes",
    "description": "Monochromatic harmony keeps the source hue and changes lightness. It is the safest system for tonal UI, cards, hover states, shadows, backgrounds, and subtle visual hierarchy.",
    "colors": [
      {
        "hex": "#FFFFFF",
        "name": "White",
        "slug": "white",
        "rgb": [
          255,
          255,
          255
        ],
        "hsl": [
          0,
          0,
          100
        ],
        "cmyk": [
          0,
          0,
          0,
          0
        ],
        "luminance": 1,
        "contrast": {
          "black": 21,
          "white": 1
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/colors/white/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/colors/white.json"
      },
      {
        "hex": "#D9DAD9",
        "name": "Aluminum",
        "slug": "aluminum",
        "rgb": [
          217,
          218,
          217
        ],
        "hsl": [
          120,
          1,
          85
        ],
        "cmyk": [
          0,
          0,
          0,
          15
        ],
        "luminance": 0.699,
        "contrast": {
          "black": 14.98,
          "white": 1.4
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A",
            "#36454F"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/colors/aluminum/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/colors/aluminum.json"
      },
      {
        "hex": "#AAACAA",
        "name": "#AAACAA",
        "slug": null,
        "rgb": [
          170,
          172,
          170
        ],
        "hsl": [
          120,
          1,
          67
        ],
        "cmyk": [
          1,
          0,
          1,
          33
        ],
        "luminance": 0.4095,
        "contrast": {
          "black": 9.19,
          "white": 2.29
        },
        "wcag": {
          "AA": [
            "#000000",
            "#1A1A1A"
          ],
          "AAA": [
            "#000000",
            "#1A1A1A"
          ]
        },
        "url": "https://www.colorsencyclopedia.com/hex/aaacaa/",
        "apiUrl": "https://www.colorsencyclopedia.com/api/hex/aaacaa.json"
      }
    ],
    "anchor": "aluminum-harmony-monochromatic"
  }
]
Signature palette
[
  "#D9DAD9",
  "#D9D8D9",
  "#D9D9D8",
  "#D8D9D9",
  "#FFFFFF",
  "#AAACAA"
]
Accessibility notes
[
  "Black contrast on Aluminum: 14.98:1",
  "White contrast on Aluminum: 1.4:1",
  "AA text options: #000000, #1A1A1A, #36454F"
]
CSS tokens
":root {\n  --color-aluminum: #D9DAD9;\n  --aluminum-complementary-1: #D9D8D9;\n  --aluminum-analogous-1: #D9D9D8;\n  --aluminum-analogous-2: #D8D9D9;\n  --aluminum-triadic-1: #D8D8D9;\n  --aluminum-triadic-2: #D9D8D8;\n  --aluminum-tetradic-1: #D8D9D9;\n  --aluminum-tetradic-2: #D9D8D9;\n  --aluminum-tetradic-3: #D9D9D8;\n  --aluminum-split-complementary-1: #D9D8D9;\n  --aluminum-split-complementary-2: #D9D8D9;\n  --aluminum-monochromatic-1: #FFFFFF;\n  --aluminum-monochromatic-2: #D9DAD9;\n  --aluminum-monochromatic-3: #AAACAA;\n}\n\n.palette-aluminum-harmony {\n  color: #111827;\n  background: linear-gradient(135deg, #D9DAD9, #D9D8D9, #D9D9D8, #D8D9D9, #FFFFFF, #AAACAA);\n}"
Full JSON dataset 
{
  "datasetVersion": "1.0.0",
  "slug": "aluminum",
  "name": "Aluminum",
  "hex": "#D9DAD9",
  "rgb": [
    217,
    218,
    217
  ],
  "hsl": [
    120,
    1,
    85
  ],
  "cmyk": [
    0,
    0,
    0,
    15
  ],
  "family": "gray",
  "temperature": "neutral",
  "tone": [
    "muted"
  ],
  "luminance": 0.699,
  "contrast": {
    "black": 14.98,
    "white": 1.4
  },
  "wcag": {
    "AA": [
      "#000000",
      "#1A1A1A",
      "#36454F"
    ],
    "AAA": [
      "#000000",
      "#1A1A1A",
      "#36454F"
    ]
  },
  "sourceColor": {
    "slug": "aluminum",
    "name": "Aluminum",
    "hex": "#D9DAD9",
    "url": "https://www.colorsencyclopedia.com/colors/aluminum/",
    "apiUrl": "https://www.colorsencyclopedia.com/api/colors/aluminum.json"
  },
  "harmonyGroups": [
    {
      "key": "complementary",
      "label": "Complementary",
      "behavior": "maximum hue contrast",
      "bestUse": "accent colors, strong calls to action, visual opposition",
      "description": "Complementary harmony uses the color opposite the source hue. It creates the strongest direct relationship in the wheel, so it is best for accents, contrast anchors, and palettes that need immediate separation.",
      "colors": [
        {
          "hex": "#D9D8D9",
          "name": "#D9D8D9",
          "slug": null,
          "rgb": [
            217,
            216,
            217
          ],
          "hsl": [
            300,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.6887,
          "contrast": {
            "black": 14.77,
            "white": 1.42
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/d9d8d9/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d8d9.json"
        }
      ],
      "anchor": "aluminum-harmony-complementary"
    },
    {
      "key": "analogous",
      "label": "Analogous",
      "behavior": "neighboring hue movement",
      "bestUse": "calm palettes, gradients, natural transitions",
      "description": "Analogous harmony uses hues close to the source color. It keeps the palette visually connected and is useful for quiet interfaces, editorial color systems, and smooth background or gradient work.",
      "colors": [
        {
          "hex": "#D9D9D8",
          "name": "#D9D9D8",
          "slug": null,
          "rgb": [
            217,
            217,
            216
          ],
          "hsl": [
            60,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.6934,
          "contrast": {
            "black": 14.87,
            "white": 1.41
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/d9d9d8/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d9d8.json"
        },
        {
          "hex": "#D8D9D9",
          "name": "#D8D9D9",
          "slug": null,
          "rgb": [
            216,
            217,
            217
          ],
          "hsl": [
            180,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.6923,
          "contrast": {
            "black": 14.85,
            "white": 1.41
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/d8d9d9/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d8d9d9.json"
        }
      ],
      "anchor": "aluminum-harmony-analogous"
    },
    {
      "key": "triadic",
      "label": "Triadic",
      "behavior": "three evenly spaced hues",
      "bestUse": "balanced contrast, playful systems, broad palette range",
      "description": "Triadic harmony places colors around the wheel at equal intervals. It gives more range than analogous harmony while keeping a stable mathematical relationship between the selected hues.",
      "colors": [
        {
          "hex": "#D8D8D9",
          "name": "#D8D8D9",
          "slug": null,
          "rgb": [
            216,
            216,
            217
          ],
          "hsl": [
            240,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.6872,
          "contrast": {
            "black": 14.74,
            "white": 1.42
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/d8d8d9/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d8d8d9.json"
        },
        {
          "hex": "#D9D8D8",
          "name": "#D9D8D8",
          "slug": null,
          "rgb": [
            217,
            216,
            216
          ],
          "hsl": [
            0,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.6882,
          "contrast": {
            "black": 14.76,
            "white": 1.42
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/d9d8d8/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d8d8.json"
        }
      ],
      "anchor": "aluminum-harmony-triadic"
    },
    {
      "key": "tetradic",
      "label": "Tetradic",
      "behavior": "two complementary pairs",
      "bestUse": "large design systems, dashboards, multi-state UI",
      "description": "Tetradic harmony creates a four-color system from two complementary relationships. It is useful when a palette needs multiple roles, but the colors should be assigned carefully so one hue remains dominant.",
      "colors": [
        {
          "hex": "#D8D9D9",
          "name": "#D8D9D9",
          "slug": null,
          "rgb": [
            216,
            217,
            217
          ],
          "hsl": [
            180,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.6923,
          "contrast": {
            "black": 14.85,
            "white": 1.41
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/d8d9d9/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d8d9d9.json"
        },
        {
          "hex": "#D9D8D9",
          "name": "#D9D8D9",
          "slug": null,
          "rgb": [
            217,
            216,
            217
          ],
          "hsl": [
            300,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.6887,
          "contrast": {
            "black": 14.77,
            "white": 1.42
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/d9d8d9/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d8d9.json"
        },
        {
          "hex": "#D9D9D8",
          "name": "#D9D9D8",
          "slug": null,
          "rgb": [
            217,
            217,
            216
          ],
          "hsl": [
            60,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.6934,
          "contrast": {
            "black": 14.87,
            "white": 1.41
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/d9d9d8/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d9d8.json"
        }
      ],
      "anchor": "aluminum-harmony-tetradic"
    },
    {
      "key": "splitComplementary",
      "label": "Split Complementary",
      "behavior": "softened complementary contrast",
      "bestUse": "brand palettes, accent pairs, less aggressive contrast",
      "description": "Split-complementary harmony replaces the direct opposite with the two hues beside it. This keeps useful contrast while reducing the visual tension of a pure complementary pair.",
      "colors": [
        {
          "hex": "#D9D8D9",
          "name": "#D9D8D9",
          "slug": null,
          "rgb": [
            217,
            216,
            217
          ],
          "hsl": [
            300,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.6887,
          "contrast": {
            "black": 14.77,
            "white": 1.42
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/d9d8d9/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d8d9.json"
        },
        {
          "hex": "#D9D8D9",
          "name": "#D9D8D9",
          "slug": null,
          "rgb": [
            217,
            216,
            217
          ],
          "hsl": [
            300,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.6887,
          "contrast": {
            "black": 14.77,
            "white": 1.42
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/d9d8d9/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/d9d8d9.json"
        }
      ],
      "anchor": "aluminum-harmony-split-complementary"
    },
    {
      "key": "monochromatic",
      "label": "Monochromatic",
      "behavior": "same hue, different values",
      "bestUse": "surfaces, states, elevation, restrained UI themes",
      "description": "Monochromatic harmony keeps the source hue and changes lightness. It is the safest system for tonal UI, cards, hover states, shadows, backgrounds, and subtle visual hierarchy.",
      "colors": [
        {
          "hex": "#FFFFFF",
          "name": "White",
          "slug": "white",
          "rgb": [
            255,
            255,
            255
          ],
          "hsl": [
            0,
            0,
            100
          ],
          "cmyk": [
            0,
            0,
            0,
            0
          ],
          "luminance": 1,
          "contrast": {
            "black": 21,
            "white": 1
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/colors/white/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/colors/white.json"
        },
        {
          "hex": "#D9DAD9",
          "name": "Aluminum",
          "slug": "aluminum",
          "rgb": [
            217,
            218,
            217
          ],
          "hsl": [
            120,
            1,
            85
          ],
          "cmyk": [
            0,
            0,
            0,
            15
          ],
          "luminance": 0.699,
          "contrast": {
            "black": 14.98,
            "white": 1.4
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A",
              "#36454F"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/colors/aluminum/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/colors/aluminum.json"
        },
        {
          "hex": "#AAACAA",
          "name": "#AAACAA",
          "slug": null,
          "rgb": [
            170,
            172,
            170
          ],
          "hsl": [
            120,
            1,
            67
          ],
          "cmyk": [
            1,
            0,
            1,
            33
          ],
          "luminance": 0.4095,
          "contrast": {
            "black": 9.19,
            "white": 2.29
          },
          "wcag": {
            "AA": [
              "#000000",
              "#1A1A1A"
            ],
            "AAA": [
              "#000000",
              "#1A1A1A"
            ]
          },
          "url": "https://www.colorsencyclopedia.com/hex/aaacaa/",
          "apiUrl": "https://www.colorsencyclopedia.com/api/hex/aaacaa.json"
        }
      ],
      "anchor": "aluminum-harmony-monochromatic"
    }
  ],
  "signaturePalette": [
    "#D9DAD9",
    "#D9D8D9",
    "#D9D9D8",
    "#D8D9D9",
    "#FFFFFF",
    "#AAACAA"
  ],
  "semanticGroups": [
    "gray harmony",
    "neutral harmony",
    "muted harmony",
    "aluminum palette system"
  ],
  "useCases": [
    "palette generation",
    "brand color exploration",
    "UI accent planning",
    "CSS design tokens",
    "AI color retrieval"
  ],
  "accessibilityNotes": [
    "Black contrast on Aluminum: 14.98:1",
    "White contrast on Aluminum: 1.4:1",
    "AA text options: #000000, #1A1A1A, #36454F"
  ],
  "relatedEndpoints": [
    "https://www.colorsencyclopedia.com/api/harmonies/aluminum.json",
    "https://www.colorsencyclopedia.com/api/colors/aluminum.json",
    "https://www.colorsencyclopedia.com/api/hex/d9dad9.json"
  ],
  "url": "https://www.colorsencyclopedia.com/harmonies/aluminum/",
  "apiUrl": "https://www.colorsencyclopedia.com/api/harmonies/aluminum.json",
  "cssSnippet": ":root {\n  --color-aluminum: #D9DAD9;\n  --aluminum-complementary-1: #D9D8D9;\n  --aluminum-analogous-1: #D9D9D8;\n  --aluminum-analogous-2: #D8D9D9;\n  --aluminum-triadic-1: #D8D8D9;\n  --aluminum-triadic-2: #D9D8D8;\n  --aluminum-tetradic-1: #D8D9D9;\n  --aluminum-tetradic-2: #D9D8D9;\n  --aluminum-tetradic-3: #D9D9D8;\n  --aluminum-split-complementary-1: #D9D8D9;\n  --aluminum-split-complementary-2: #D9D8D9;\n  --aluminum-monochromatic-1: #FFFFFF;\n  --aluminum-monochromatic-2: #D9DAD9;\n  --aluminum-monochromatic-3: #AAACAA;\n}\n\n.palette-aluminum-harmony {\n  color: #111827;\n  background: linear-gradient(135deg, #D9DAD9, #D9D8D9, #D9D9D8, #D8D9D9, #FFFFFF, #AAACAA);\n}"
}
Dataset manifest Version 1.0.0 Build hash published in manifest Canonical page

CSS Harmony Tokens

Use these tokens when Aluminum needs a complete palette system instead of a single color variable.

:root {
  --color-aluminum: #D9DAD9;
  --aluminum-complementary-1: #D9D8D9;
  --aluminum-analogous-1: #D9D9D8;
  --aluminum-analogous-2: #D8D9D9;
  --aluminum-triadic-1: #D8D8D9;
  --aluminum-triadic-2: #D9D8D8;
  --aluminum-tetradic-1: #D8D9D9;
  --aluminum-tetradic-2: #D9D8D9;
  --aluminum-tetradic-3: #D9D9D8;
  --aluminum-split-complementary-1: #D9D8D9;
  --aluminum-split-complementary-2: #D9D8D9;
  --aluminum-monochromatic-1: #FFFFFF;
  --aluminum-monochromatic-2: #D9DAD9;
  --aluminum-monochromatic-3: #AAACAA;
}

.palette-aluminum-harmony {
  color: #111827;
  background: linear-gradient(135deg, #D9DAD9, #D9D8D9, #D9D9D8, #D8D9D9, #FFFFFF, #AAACAA);
}

Aluminum Harmony Groups

Open a group to inspect its generated colors, intended behavior, and best design use. Anchor links above open the matching group directly.

Complementary Harmony1 colors · maximum hue contrast

Complementary harmony uses the color opposite the source hue. It creates the strongest direct relationship in the wheel, so it is best for accents, contrast anchors, and palettes that need immediate separation.

Behaviormaximum hue contrast
Best useaccent colors, strong calls to action, visual opposition
Source colorAluminum · #D9DAD9
#D9D8D9#D9D8D9
Analogous Harmony2 colors · neighboring hue movement

Analogous harmony uses hues close to the source color. It keeps the palette visually connected and is useful for quiet interfaces, editorial color systems, and smooth background or gradient work.

Behaviorneighboring hue movement
Best usecalm palettes, gradients, natural transitions
Source colorAluminum · #D9DAD9
#D9D9D8#D9D9D8
#D8D9D9#D8D9D9
Triadic Harmony2 colors · three evenly spaced hues

Triadic harmony places colors around the wheel at equal intervals. It gives more range than analogous harmony while keeping a stable mathematical relationship between the selected hues.

Behaviorthree evenly spaced hues
Best usebalanced contrast, playful systems, broad palette range
Source colorAluminum · #D9DAD9
#D8D8D9#D8D8D9
#D9D8D8#D9D8D8
Tetradic Harmony3 colors · two complementary pairs

Tetradic harmony creates a four-color system from two complementary relationships. It is useful when a palette needs multiple roles, but the colors should be assigned carefully so one hue remains dominant.

Behaviortwo complementary pairs
Best uselarge design systems, dashboards, multi-state UI
Source colorAluminum · #D9DAD9
#D8D9D9#D8D9D9
#D9D8D9#D9D8D9
#D9D9D8#D9D9D8
Split Complementary Harmony2 colors · softened complementary contrast

Split-complementary harmony replaces the direct opposite with the two hues beside it. This keeps useful contrast while reducing the visual tension of a pure complementary pair.

Behaviorsoftened complementary contrast
Best usebrand palettes, accent pairs, less aggressive contrast
Source colorAluminum · #D9DAD9
#D9D8D9#D9D8D9
#D9D8D9#D9D8D9
Monochromatic Harmony3 colors · same hue, different values

Monochromatic harmony keeps the source hue and changes lightness. It is the safest system for tonal UI, cards, hover states, shadows, backgrounds, and subtle visual hierarchy.

Behaviorsame hue, different values
Best usesurfaces, states, elevation, restrained UI themes
Source colorAluminum · #D9DAD9
White#FFFFFF
Aluminum#D9DAD9
#AAACAA#AAACAA

Related Harmony Guides

Aluminum color referenceOpen the main color page with conversions, CSS, JSON, WCAG, variants, and related colors.Aluminum harmonies JSONOpen the machine-readable harmony dataset.Aluminum color APIOpen the complete source color entity JSON.Aluminum paletteSee the generated palette system based on this color.Gray colorsBrowse related named colors in the gray family.Neutral colorsExplore neutral colors across the editorial dataset.Muted colorsExplore muted colors with similar visual behavior.