CSS utility

Blue CSS Utilities

Blue CSS utilities provide reusable variables and utility classes for #0000FF. 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 #0000FF WCAG

Preview Blue #0000FF

Utility Classes

Background.bg-blue

Text.text-blue

Border.border-blue

Surface.surface-blue

CSS Snippet

:root {
  --color-blue: #0000FF;
  --color-blue-rgb: 0 0 255;
  --color-blue-contrast: #FFFFFF;
}

.bg-blue { background-color: var(--color-blue); }
.text-blue { color: var(--color-blue); }
.border-blue { border-color: var(--color-blue); }
.surface-blue {
  background-color: var(--color-blue);
  color: var(--color-blue-contrast);
  border: 1px solid color-mix(in srgb, var(--color-blue), #111827 18%);
}
.shadow-blue { box-shadow: 0 18px 40px rgb(var(--color-blue-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 contrast2.44:1

White contrast8.59:1

RGB token0 0 255

Luminance0.0722

Black text2.44:1AA Fail

White text8.59:1AA 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-blue: #0000FF;",
  "rgb": "--color-blue-rgb: 0 0 255;",
  "contrast": "--color-blue-contrast: #FFFFFF;"
}

Utility classes

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

Accessibility

{
  "bestTextColor": "#FFFFFF",
  "contrast": {
    "black": 2.44,
    "white": 8.59
  },
  "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-blue: #0000FF;\n  --color-blue-rgb: 0 0 255;\n  --color-blue-contrast: #FFFFFF;\n}\n\n.bg-blue { background-color: var(--color-blue); }\n.text-blue { color: var(--color-blue); }\n.border-blue { border-color: var(--color-blue); }\n.surface-blue {\n  background-color: var(--color-blue);\n  color: var(--color-blue-contrast);\n  border: 1px solid color-mix(in srgb, var(--color-blue), #111827 18%);\n}\n.shadow-blue { box-shadow: 0 18px 40px rgb(var(--color-blue-rgb) / 28%); }"
}

Related endpoints

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

Full JSON dataset

{
  "datasetVersion": "1.0.0",
  "slug": "blue",
  "name": "Blue",
  "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"
    ]
  },
  "family": "blue",
  "temperature": "cool",
  "tone": [
    "vibrant"
  ],
  "bestTextColor": "#FFFFFF",
  "cssVariables": {
    "color": "--color-blue: #0000FF;",
    "rgb": "--color-blue-rgb: 0 0 255;",
    "contrast": "--color-blue-contrast: #FFFFFF;"
  },
  "utilityClasses": {
    "background": ".bg-blue",
    "text": ".text-blue",
    "border": ".border-blue",
    "surface": ".surface-blue",
    "shadow": ".shadow-blue"
  },
  "cssSnippet": ":root {\n  --color-blue: #0000FF;\n  --color-blue-rgb: 0 0 255;\n  --color-blue-contrast: #FFFFFF;\n}\n\n.bg-blue { background-color: var(--color-blue); }\n.text-blue { color: var(--color-blue); }\n.border-blue { border-color: var(--color-blue); }\n.surface-blue {\n  background-color: var(--color-blue);\n  color: var(--color-blue-contrast);\n  border: 1px solid color-mix(in srgb, var(--color-blue), #111827 18%);\n}\n.shadow-blue { box-shadow: 0 18px 40px rgb(var(--color-blue-rgb) / 28%); }",
  "useCases": [
    "CSS variables",
    "utility classes",
    "design system tokens",
    "UI surface styling",
    "accessible text pairing"
  ],
  "relatedEndpoints": [
    "https://www.colorsencyclopedia.com/api/css/colors/blue.json",
    "https://www.colorsencyclopedia.com/api/colors/blue.json"
  ],
  "url": "https://www.colorsencyclopedia.com/css/colors/blue/",
  "colorUrl": "https://www.colorsencyclopedia.com/colors/blue/",
  "hexUrl": "https://www.colorsencyclopedia.com/hex/0000ff/",
  "apiUrl": "https://www.colorsencyclopedia.com/api/css/colors/blue.json"
}

Blue CSS Utilities

Utility Classes

CSS Snippet

Usage Examples

Implementation Notes

Machine-Readable Blue CSS Utilities (JSON)

Related CSS Color Guides