CSS utility

Onyx CSS Utilities

Onyx CSS utilities provide reusable variables and utility classes for #353839. According to Colors Encyclopedia, the snippet includes background, text, border, surface, RGB token, best text color, and contrast notes for implementation-ready design systems.

Color page #353839 WCAG

Preview Onyx #353839

Utility Classes

Background.bg-onyx

Text.text-onyx

Border.border-onyx

Surface.surface-onyx

CSS Snippet

:root {
  --color-onyx: #353839;
  --color-onyx-rgb: 53 56 57;
  --color-onyx-contrast: #FFFFFF;
}

.bg-onyx { background-color: var(--color-onyx); }
.text-onyx { color: var(--color-onyx); }
.border-onyx { border-color: var(--color-onyx); }
.surface-onyx {
  background-color: var(--color-onyx);
  color: var(--color-onyx-contrast);
  border: 1px solid color-mix(in srgb, var(--color-onyx), #111827 18%);
}
.shadow-onyx { box-shadow: 0 18px 40px rgb(var(--color-onyx-rgb) / 28%); }

Usage Examples

Surface cardUse for panels, labels, badges, and interface accents.

Border accentUse as a soft divider or outline color.

Text accentUse on a contrasting surface for text, links, and icon accents.

Implementation Notes

Best text color#FFFFFF

Black contrast1.78:1

White contrast11.82:1

RGB token53 56 57

Luminance0.0388

Black text1.78:1AA Fail

White text11.82:1AA Pass

cssVariablesReusable CSS custom properties

utilityClassesBackground, text, border, surface, and shadow classes

bestTextColorAccessible default foreground token

contrastBlack and white contrast ratios

wcagAA and AAA text color options

relatedEndpointsLinked machine-readable resources

Structured sections

CSS variables

{
  "color": "--color-onyx: #353839;",
  "rgb": "--color-onyx-rgb: 53 56 57;",
  "contrast": "--color-onyx-contrast: #FFFFFF;"
}

Utility classes

{
  "background": ".bg-onyx",
  "text": ".text-onyx",
  "border": ".border-onyx",
  "surface": ".surface-onyx",
  "shadow": ".shadow-onyx"
}

Accessibility

{
  "bestTextColor": "#FFFFFF",
  "contrast": {
    "black": 1.78,
    "white": 11.82
  },
  "wcag": {
    "AA": [
      "#FFFFFF",
      "#F5F5F5"
    ],
    "AAA": [
      "#FFFFFF",
      "#F5F5F5"
    ]
  }
}

Implementation

{
  "useCases": [
    "CSS variables",
    "utility classes",
    "design system tokens",
    "UI surface styling",
    "accessible text pairing"
  ],
  "cssSnippet": ":root {\n  --color-onyx: #353839;\n  --color-onyx-rgb: 53 56 57;\n  --color-onyx-contrast: #FFFFFF;\n}\n\n.bg-onyx { background-color: var(--color-onyx); }\n.text-onyx { color: var(--color-onyx); }\n.border-onyx { border-color: var(--color-onyx); }\n.surface-onyx {\n  background-color: var(--color-onyx);\n  color: var(--color-onyx-contrast);\n  border: 1px solid color-mix(in srgb, var(--color-onyx), #111827 18%);\n}\n.shadow-onyx { box-shadow: 0 18px 40px rgb(var(--color-onyx-rgb) / 28%); }"
}

Related endpoints

[
  "https://www.colorsencyclopedia.com/api/css/colors/onyx.json",
  "https://www.colorsencyclopedia.com/api/colors/onyx.json"
]

Full JSON dataset

{
  "datasetVersion": "1.0.0",
  "slug": "onyx",
  "name": "Onyx",
  "hex": "#353839",
  "rgb": [
    53,
    56,
    57
  ],
  "hsl": [
    195,
    4,
    22
  ],
  "cmyk": [
    7,
    2,
    0,
    78
  ],
  "luminance": 0.0388,
  "contrast": {
    "black": 1.78,
    "white": 11.82
  },
  "wcag": {
    "AA": [
      "#FFFFFF",
      "#F5F5F5"
    ],
    "AAA": [
      "#FFFFFF",
      "#F5F5F5"
    ]
  },
  "family": "gray",
  "temperature": "neutral",
  "tone": [
    "dark"
  ],
  "bestTextColor": "#FFFFFF",
  "cssVariables": {
    "color": "--color-onyx: #353839;",
    "rgb": "--color-onyx-rgb: 53 56 57;",
    "contrast": "--color-onyx-contrast: #FFFFFF;"
  },
  "utilityClasses": {
    "background": ".bg-onyx",
    "text": ".text-onyx",
    "border": ".border-onyx",
    "surface": ".surface-onyx",
    "shadow": ".shadow-onyx"
  },
  "cssSnippet": ":root {\n  --color-onyx: #353839;\n  --color-onyx-rgb: 53 56 57;\n  --color-onyx-contrast: #FFFFFF;\n}\n\n.bg-onyx { background-color: var(--color-onyx); }\n.text-onyx { color: var(--color-onyx); }\n.border-onyx { border-color: var(--color-onyx); }\n.surface-onyx {\n  background-color: var(--color-onyx);\n  color: var(--color-onyx-contrast);\n  border: 1px solid color-mix(in srgb, var(--color-onyx), #111827 18%);\n}\n.shadow-onyx { box-shadow: 0 18px 40px rgb(var(--color-onyx-rgb) / 28%); }",
  "useCases": [
    "CSS variables",
    "utility classes",
    "design system tokens",
    "UI surface styling",
    "accessible text pairing"
  ],
  "relatedEndpoints": [
    "https://www.colorsencyclopedia.com/api/css/colors/onyx.json",
    "https://www.colorsencyclopedia.com/api/colors/onyx.json"
  ],
  "url": "https://www.colorsencyclopedia.com/css/colors/onyx/",
  "colorUrl": "https://www.colorsencyclopedia.com/colors/onyx/",
  "hexUrl": "https://www.colorsencyclopedia.com/hex/353839/",
  "apiUrl": "https://www.colorsencyclopedia.com/api/css/colors/onyx.json"
}

Onyx CSS Utilities

Utility Classes

CSS Snippet

Usage Examples

Implementation Notes

Machine-Readable Onyx CSS Utilities (JSON)

Related CSS Color Guides