Named color

Blue

Blue is a vibrant blue color with HEX #0000FF. According to Colors Encyclopedia, it has RGB 0, 0, 255, HSL 240, 100%, 50%, cool temperature, and is useful for web design, CSS color systems, and UI prototyping.

#0000FF blue cool vibrant

HEX #0000FF

RGB rgb(0, 0, 255)

HSL hsl(240 100% 50%)

CMYK cmyk(100, 100, 0, 0)

Luminance 0.0722

Contrast Black 2.44:1White 8.59:1

CSS Utilities

--color-blue: #0000FF;
.bg-blue { background-color: #0000FF; }
.text-blue { color: #0000FF; }

Open CSS utility pageReusable variables, classes, examples, and implementation notes

Luminance0.0722

Black text2.44:1AA Fail

White text8.59:1AA Pass

hexCanonical HEX value

rgbRed, green, blue channels

hslHue, saturation, lightness

cmykApproximate print conversion

wcagAA and AAA contrast options

harmoniesMathematical harmony sets

variantsGenerated tone variants

nearestColorsKnowledge graph neighbors

Structured sections

Color systems

{
  "hex": "#0000FF",
  "rgb": [
    0,
    0,
    255
  ],
  "hsl": [
    240,
    100,
    50
  ],
  "cmyk": [
    100,
    100,
    0,
    0
  ],
  "luminance": 0.0722,
  "contrast": {
    "black": 2.44,
    "white": 8.59
  }
}

WCAG

{
  "AA": [
    "#FFFFFF",
    "#F5F5F5"
  ],
  "AAA": [
    "#FFFFFF",
    "#F5F5F5"
  ]
}

Harmonies

{
  "complementary": "#FFFF00",
  "analogous": [
    "#007FFF",
    "#7F00FF"
  ],
  "triadic": [
    "#FF0000",
    "#00FF00"
  ],
  "tetradic": [
    "#FF0080",
    "#FFFF00",
    "#00FF80"
  ],
  "splitComplementary": [
    "#FF8000",
    "#80FF00"
  ],
  "monochromatic": [
    "#5C5CFF",
    "#0000FF",
    "#0000A3"
  ]
}

Variants

{
  "light": "#5C5CFF",
  "dark": "#0000A3",
  "saturated": "#0000FF",
  "desaturated": "#1C1CE3",
  "pastel": "#8989F5",
  "neon": "#2929FF"
}

Pairings

{
  "best": [
    "#FFFFFF",
    "#FFFF00",
    "#007FFF",
    "#7F00FF"
  ],
  "avoid": [
    "#1C1CE3",
    "#5C5CFF"
  ],
  "neutral": [
    "#1A1A1A",
    "#F5F5F5",
    "#E8E8E4"
  ],
  "highContrast": [
    "#FFFFFF"
  ],
  "lowContrast": [
    "#5C5CFF",
    "#1C1CE3"
  ]
}

Knowledge graph

{
  "nearestColors": [
    "medium-blue",
    "han-purple",
    "neon-blue",
    "zaffre",
    "persian-blue"
  ],
  "generatedPalettes": [
    "blue"
  ],
  "generatedComparisons": [
    "blue-vs-han-purple",
    "blue-vs-medium-blue"
  ],
  "relatedFamilies": [
    "/colors/by-family/blue",
    "/colors/by-temperature/cool",
    "/colors/by-tone/vibrant"
  ],
  "relatedTools": [
    "/harmonies/blue",
    "/wcag/blue",
    "/css/colors/blue",
    "/hex/0000ff"
  ],
  "semanticRelations": {
    "broader": [
      "/colors/by-family/blue",
      "/colors/by-temperature/cool",
      "/colors/by-tone/vibrant"
    ],
    "narrower": [
      "/palettes/blue"
    ],
    "related": [
      "/colors/medium-blue",
      "/colors/han-purple",
      "/colors/neon-blue",
      "/colors/zaffre",
      "/colors/persian-blue",
      "/compare/blue-vs-han-purple",
      "/compare/blue-vs-medium-blue",
      "/harmonies/blue",
      "/wcag/blue",
      "/css/colors/blue",
      "/hex/0000ff"
    ]
  }
}

Full JSON dataset

{
  "slug": "blue",
  "name": "Blue",
  "cssName": "blue",
  "hex": "#0000FF",
  "family": "blue",
  "temperature": "cool",
  "tone": [
    "vibrant"
  ],
  "uses": [
    "web design",
    "CSS color systems",
    "UI prototyping"
  ],
  "psychology": {
    "associations": [
      "context dependent"
    ],
    "contexts": [
      "web interfaces",
      "design systems",
      "technical color references"
    ],
    "avoidIn": [
      "claims that require brand or cultural specificity"
    ]
  },
  "aliases": [
    "blue"
  ],
  "sourceType": "standard",
  "confidence": "high",
  "sourceUrl": "https://www.w3.org/TR/css-color-4/#named-colors",
  "origin": {
    "type": "css",
    "notes": "Standard CSS named color."
  },
  "reviewStatus": "auto",
  "editorialNotes": "Generated from CSS named color data and computed color-system properties.",
  "tags": [
    "blue",
    "cool",
    "vibrant",
    "web-design",
    "css-color-systems",
    "ui-prototyping",
    "context-dependent"
  ],
  "popularity": 82,
  "rgb": [
    0,
    0,
    255
  ],
  "hsl": [
    240,
    100,
    50
  ],
  "cmyk": [
    100,
    100,
    0,
    0
  ],
  "luminance": 0.0722,
  "contrast": {
    "black": 2.44,
    "white": 8.59
  },
  "harmonies": {
    "complementary": "#FFFF00",
    "analogous": [
      "#007FFF",
      "#7F00FF"
    ],
    "triadic": [
      "#FF0000",
      "#00FF00"
    ],
    "tetradic": [
      "#FF0080",
      "#FFFF00",
      "#00FF80"
    ],
    "splitComplementary": [
      "#FF8000",
      "#80FF00"
    ],
    "monochromatic": [
      "#5C5CFF",
      "#0000FF",
      "#0000A3"
    ]
  },
  "variants": {
    "light": "#5C5CFF",
    "dark": "#0000A3",
    "saturated": "#0000FF",
    "desaturated": "#1C1CE3",
    "pastel": "#8989F5",
    "neon": "#2929FF"
  },
  "wcag": {
    "AA": [
      "#FFFFFF",
      "#F5F5F5"
    ],
    "AAA": [
      "#FFFFFF",
      "#F5F5F5"
    ]
  },
  "css": {
    "variable": "--color-blue: #0000FF;",
    "utility": ".bg-blue { background-color: #0000FF; }",
    "textUtility": ".text-blue { color: #0000FF; }"
  },
  "nearestColors": [
    "medium-blue",
    "han-purple",
    "neon-blue",
    "zaffre",
    "persian-blue"
  ],
  "generatedPalettes": [
    "blue"
  ],
  "generatedComparisons": [
    "blue-vs-han-purple",
    "blue-vs-medium-blue"
  ],
  "relatedFamilies": [
    "/colors/by-family/blue",
    "/colors/by-temperature/cool",
    "/colors/by-tone/vibrant"
  ],
  "relatedTools": [
    "/harmonies/blue",
    "/wcag/blue",
    "/css/colors/blue",
    "/hex/0000ff"
  ],
  "semanticRelations": {
    "broader": [
      "/colors/by-family/blue",
      "/colors/by-temperature/cool",
      "/colors/by-tone/vibrant"
    ],
    "narrower": [
      "/palettes/blue"
    ],
    "related": [
      "/colors/medium-blue",
      "/colors/han-purple",
      "/colors/neon-blue",
      "/colors/zaffre",
      "/colors/persian-blue",
      "/compare/blue-vs-han-purple",
      "/compare/blue-vs-medium-blue",
      "/harmonies/blue",
      "/wcag/blue",
      "/css/colors/blue",
      "/hex/0000ff"
    ]
  },
  "pairings": {
    "best": [
      "#FFFFFF",
      "#FFFF00",
      "#007FFF",
      "#7F00FF"
    ],
    "avoid": [
      "#1C1CE3",
      "#5C5CFF"
    ],
    "neutral": [
      "#1A1A1A",
      "#F5F5F5",
      "#E8E8E4"
    ],
    "highContrast": [
      "#FFFFFF"
    ],
    "lowContrast": [
      "#5C5CFF",
      "#1C1CE3"
    ]
  }
}

Color meaning and use

About Blue Color

Blue sits in the blue family with cool temperature and vibrant visual character. Standard CSS named color.

Its common associations include context dependent, which makes it relevant for web interfaces and design systems. In design work, Blue is most useful for web design, css color systems, and ui prototyping, especially when paired with white text for stronger contrast.

WCAG Accessibility

Contrast checks for Blue against black and white text.

Black text2.44:1AA Fail

White text8.59:1AA Pass

AA text options#FFFFFF, #F5F5F5

AAA text options#FFFFFF, #F5F5F5

Open WCAG pageDetailed contrast notes, warnings, alternatives, and UI examples

Similar Colors

Medium Blue#0000CD

Han Purple#5218FA

Neon Blue#1F51FF

Zaffre#0014A8

Persian Blue#1C39BB

Color Harmonies

Yellow#FFFF00

#007FFF#007FFF

#7F00FF#7F00FF

Red#FF0000

Lime#00FF00

Open full Blue harmony pageComplementary, analogous, triadic, tetradic, split, and monochromatic sets

Variants

#5C5CFF#5C5CFF

#0000A3#0000A3

Blue#0000FF

#1C1CE3#1C1CE3

#8989F5#8989F5

#2929FF#2929FF

Pairings

White#FFFFFF

Yellow#FFFF00

#007FFF#007FFF

#7F00FF#7F00FF

Matte Black#1A1A1A

White Smoke#F5F5F5

Blue

CSS Utilities

Machine-Readable Color Data (JSON)

About Blue Color

Related Color Guides

WCAG Accessibility

Similar Colors

Color Harmonies

Variants

Pairings