Color reference

#2131BD color reference

Vivid Dark Blue

This is a vivid, dark blue under the deterministic OKLCH hue, lightness, and chroma ranges. Its closest standardized CSS named color is Medium Blue (#0000CD), measured with straight-line OKLab distance.

Descriptive label
Vivid Dark Blue
Recommended text
White · 9.38:1
Relative luminance
0.061941
Build a palette from #2131BD in Palette Generator Convert #2131BD in Color Converter
Formats UI preview Contrast 50–900 scale Harmonies Matches Related colors Color vision Exports

Copyable values

#2131BD in common color formats

Values are calculated from the same opaque sRGB color. Display rounding does not alter the internal calculations.

Color conversions for #2131BD
Format Value Action
HEX #2131BD
RGB rgb(33 49 189)
HSL hsl(234 70.27% 43.53%)
HSV hsv(234 82.54% 74.12%)
HWB hwb(234 12.94% 25.88%)
XYZ D65 color(xyz-d65 0.109098 0.061937 0.487663)
LAB lab(28.446% 36.2876 -75.9798)
LCH lch(28.446% 84.2005 295.5289)
OKLAB oklab(41.437% -0.006123 -0.214117)
OKLCH oklch(41.437% 0.214205 268.362)

Real-world test

Try #2131BD on interface components

Preview the source as a primary action, subtle status, form treatment, and card surface. Persistent state controls help touch and keyboard users inspect the same normal, hover, and active colors.

Normal state uses #2131BD with white text at 9.38:1.

Action

Primary button

Use the controls above or point to and press the button to inspect its visual states.

Status

Subtle alert badge

A 12% source tint over white provides the background; readable text is selected separately.

Ready for review

Form

Border and focus ring

Source ring on white: 9.38:1 · meets the 3:1 non-text threshold where applicable.

Surface

Card component

The selected state becomes the card surface with its strongest black-or-white text pairing.

Design system Color decision ready Review states and surrounding surfaces before shipping.

Accessibility diagnostics

WCAG contrast for exact color pairs

Each result applies only to the named foreground, background, text size, and requirement. It is not a complete accessibility or component-conformance claim.

Source #2131BD Exact pair assessment Results for source text on white appear below.

On white

9.38:1

  • Pass AA normal text · 4.5:1
  • Pass AAA normal text · 7:1
  • Pass AA large text · 3:1
  • Pass UI/non-text where applicable · 3:1
Source #2131BD Exact pair assessment Results for source text on black appear below.

On black

2.24:1

  • Fail AA normal text · 4.5:1
  • Fail AAA normal text · 7:1
  • Fail AA large text · 3:1
  • Fail UI/non-text where applicable · 3:1

Use guidance

What this color may be suitable for

Pass in a tested context

Normal-sized text

#2131BD reaches 8.98:1 on Hue Codex paper, meeting WCAG AA for normal text in that exact pairing.

Potential fit

Controls and interface graphics

Against Hue Codex paper, the color reaches 8.98:1. That meets the 3:1 color-contrast threshold where WCAG 1.4.11 applies, but states, shape, and non-color cues still need review.

Readable pairing available

Colored surface or button fill

White text provides the stronger black/white pairing on #2131BD at 9.38:1. This validates only that text pair, not hover, focus, disabled, or adjacent-color states.

Distinctive accent

Palette role

Its OKLCH chroma of 0.2142 gives it enough visual presence for an accent or primary role when the tested foreground and neighboring colors pass.

Pair available

Color used as foreground

The stronger black/white background is white at 9.38:1. Always retest against the actual rendered background and text size.

Tested backgrounds

Foreground pairing comparison

#2131BD foreground contrast on tested backgrounds
Pair Background Contrast ratio
White#FFFFFF 9.38:1
Hue Codex paper#FBFAF5 8.98:1
Soft neutral#F2EFE6 8.16:1
Black#000000 2.24:1
Hue Codex ink#10212B 1.76:1
Check #2131BD on another background in Contrast Checker

Design-system starting point

A perceptual 50–900 reference scale

The source color is preserved at the nearest lightness step. Other swatches keep its OKLCH hue, moderate chroma toward the extremes, and reduce chroma only when needed to remain in sRGB.

50
100
200
300
400
500
600
700 #2131BD Source
800
900

This is a Hue Codex reference scale, not a claim that the values match Tailwind, Material, or another framework’s named palette.

Adjust the #2131BD scale in Tints, Shades & Tones

Color relationships

Complementary, analogous, and triadic colors

Hue rotations use OKLCH while preserving lightness and requested chroma. When a rotated result falls outside sRGB, chroma is reduced deterministically and disclosed.

Complementary

Source #2131BD
Complement Chroma fitted to sRGB

Analogous

Source #2131BD
Analogous −30° Chroma fitted to sRGB
Analogous +30°

Triadic

Source #2131BD
Triad +120° Chroma fitted to sRGB
Triad +240° Chroma fitted to sRGB

Applied pairing

A small interface check

The source anchors the main action while the complement marks a secondary status. Contrast is selected separately for each fill.

Project color Vivid Dark Blue
Complement
Explore #2131BD in Color Harmonies

Distance matching

Closest standardized and framework colors

Matches use straight-line OKLab distance ×100. A smaller value means the coordinates are closer in this model; it is not a claim that two tokens are interchangeable in a design system.

CSS named color

Medium Blue

#0000CD

OKLab distance ×100: 6.27

Tailwind v4 default

blue-800

oklch(42.4% 0.199 265.638)

OKLab distance ×100: 2.05 · sRGB preview #193CB8

Print boundary

Pantone match not estimated

Reliable print matching needs licensed reference data plus a defined ink, paper, profile, and viewing condition.

Read the print methodology

Color-vision screening

Approximate color-vision-deficiency views

These encoded-sRGB matrix previews are screening approximations. They help reveal possible color-only distinctions but do not reproduce every person’s vision or establish accessibility conformance.

Original#2131BD
Approx.

Protanopia

Red-vision deficiency approximation

Original#2131BD
Approx.

Deuteranopia

Green-vision deficiency approximation

Original#2131BD
Approx.

Tritanopia

Blue-yellow deficiency approximation

Original#2131BD
Approx.

Achromatopsia

Monochromatic-vision approximation

Test #2131BD with a complete palette in the CVD Simulator

Ready to use

Copy framework-ready color tokens

Exports preserve the source, readable foreground, and generated 50–900 scale. Tailwind v4 CSS-first and Tailwind v3 JavaScript-config formats are labeled separately.

CSS custom properties

Semantic aliases and the complete 50–900 scale.

:root {
  --color-primary: #2131BD;
  --color-on-primary: #FFFFFF;
  --color-primary-oklch: oklch(41.437% 0.214205 268.362);
  --color-primary-50: #F1F5FF;
  --color-primary-100: #D0DEFF;
  --color-primary-200: #ACC2FF;
  --color-primary-300: #87A6FF;
  --color-primary-400: #6589FC;
  --color-primary-500: #4C6EE8;
  --color-primary-600: #3552D3;
  --color-primary-700: #2131BD;
  --color-primary-800: #16199C;
  --color-primary-900: #0C0075;
}

Tailwind v4 CSS-first theme

Current @theme syntax for bg-brand, text-brand, and scale utilities.

@import "tailwindcss";

@theme {
  --color-brand: #2131BD;
  --color-brand-foreground: #FFFFFF;
  --color-brand-50: #F1F5FF;
  --color-brand-100: #D0DEFF;
  --color-brand-200: #ACC2FF;
  --color-brand-300: #87A6FF;
  --color-brand-400: #6589FC;
  --color-brand-500: #4C6EE8;
  --color-brand-600: #3552D3;
  --color-brand-700: #2131BD;
  --color-brand-800: #16199C;
  --color-brand-900: #0C0075;
}

Tailwind v3 / legacy config

CommonJS theme.extend.colors for JavaScript-config projects.

module.exports = {
  theme: {
    extend: {
      colors: {
        brand: {
          '50': '#F1F5FF',
          '100': '#D0DEFF',
          '200': '#ACC2FF',
          '300': '#87A6FF',
          '400': '#6589FC',
          '500': '#4C6EE8',
          '600': '#3552D3',
          '700': '#2131BD',
          '800': '#16199C',
          '900': '#0C0075',
          DEFAULT: '#2131BD',
          foreground: '#FFFFFF',
        },
      },
    },
  },
};

Sass variables

Semantic source, foreground, OKLCH, and scale variables.

$color-primary: #2131BD;
$color-on-primary: #FFFFFF;
$color-primary-oklch: oklch(41.437% 0.214205 268.362);
$color-primary-50: #F1F5FF;
$color-primary-100: #D0DEFF;
$color-primary-200: #ACC2FF;
$color-primary-300: #87A6FF;
$color-primary-400: #6589FC;
$color-primary-500: #4C6EE8;
$color-primary-600: #3552D3;
$color-primary-700: #2131BD;
$color-primary-800: #16199C;
$color-primary-900: #0C0075;

Modern color-mix()

Static fallbacks followed by OKLab tint and shade declarations.

:root {
  --color-primary: #2131BD;
  --color-primary-tint: #ACC2FF;
  --color-primary-tint: color-mix(in oklab, var(--color-primary) 72%, white);
  --color-primary-shade: #2131BD;
  --color-primary-shade: color-mix(in oklab, var(--color-primary) 82%, black);
}

JSON design data

Source formats, readable text, and the generated scale.

{
    "name": "Vivid Dark Blue",
    "hex": "#2131BD",
    "rgb": "rgb(33 49 189)",
    "oklch": "oklch(41.437% 0.214205 268.362)",
    "recommendedText": "#FFFFFF",
    "scale": {
        "50": "#F1F5FF",
        "100": "#D0DEFF",
        "200": "#ACC2FF",
        "300": "#87A6FF",
        "400": "#6589FC",
        "500": "#4C6EE8",
        "600": "#3552D3",
        "700": "#2131BD",
        "800": "#16199C",
        "900": "#0C0075"
    }
}

Continue the decision

Use #2131BD in a complete workflow

Reference values are a starting point. Test the color in its real role, background, states, typography, and surrounding palette before shipping.

Adjust #2131BD in Color PickerStart with this exact color and white as the working background for role and accessibility decisions. Build a palette from #2131BD in Palette GeneratorUse this exact HEX as the seed for a deterministic, role-based palette. Check #2131BD on white in Contrast CheckerStart with this color as the foreground and white as the background, then test the real pair.