TwoColorPalette

Blue and Indigo color palette

nearest CSS color: dodgerblue · 0.036
nearest CSS color: indigo · 0

The two colors sit 42 degrees apart on the wheel, both cool but with one foot in pure blue and the other already deep in purple. That closeness is what makes them work as a gradient. Blend them and you land on a saturated blue-purple (#504ABB) that feels like a natural midpoint rather than a muddy compromise.

For web work, this is a familiar Tailwind move: Blue at #3B82F6 as the lighter, friendlier end, Indigo at #4B0082 as the rich anchor. The 3.52:1 between them passes AA for large text only, so treat them as decorative partners rather than text-on-background. They shine in hero gradients, button hovers, and dark UI accents where the shift from bright blue into deep purple does the visual work.

See Blue and Indigo in use

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Blue Tailwind scale (50-900)

Indigo Tailwind scale (50-900)

Blue to Indigo blend

A continuous interpolation from Blue to Indigo, sampled into the 10 steps below. Tap any swatch to copy its hex.

Why Blue and Indigo blend best in OKLab

The same two colors blended three ways. This site uses OKLab, which keeps the blend smooth and evenly lit. The other two are shown so you can see what to avoid: sRGB darkens and muddies the middle, and HSL detours through colors that are not in your palette.

OKLabsmooth, evenly lit (used here)
sRGBmuddy, darker middle
HSLdetours through other hues

Accessibility

AA large ✓AA normal ✗AAA ✗

Do not place Blue text on Indigo (or the reverse) for body copy. For readable text, pair a dark scale step such as blue-800 or indigo-900 with a light one like indigo-50.

Contrast pairing grid

Rows are Blue steps, columns are Indigo steps. Each mark is a Blue step shown on a Indigo step: a check means it clears WCAG AA for text (4.5:1). If you can read the mark, the pairing is legible.

50100200300400500600700800900
50
100
200
300
400
500
600
700
800
900

✓ passes AA ✗ fails AA

Copy for Tailwind

Tailwind v4 — @theme (paste into your CSS)
@theme {
  --color-blue-50: #F3F8FF;
  --color-blue-100: #E7F1FF;
  --color-blue-200: #D4E5FF;
  --color-blue-300: #B9D4FF;
  --color-blue-400: #94BDFE;
  --color-blue-500: #3B82F6;
  --color-blue-600: #2E69C9;
  --color-blue-700: #214E98;
  --color-blue-800: #0F2C5A;
  --color-blue-900: #030F27;

  --color-indigo-50: #F3F0F8;
  --color-indigo-100: #E7E2F1;
  --color-indigo-200: #D4CAE5;
  --color-indigo-300: #B9A9D5;
  --color-indigo-400: #967CBD;
  --color-indigo-500: #4B0082;
  --color-indigo-600: #3C0069;
  --color-indigo-700: #2B004E;
  --color-indigo-800: #16002C;
  --color-indigo-900: #05000F;
}
Tailwind v3 — tailwind.config.js
// tailwind.config.js
module.exports = {
  theme: {
    extend: {
      colors: {
        'blue': {
        50: '#F3F8FF',
        100: '#E7F1FF',
        200: '#D4E5FF',
        300: '#B9D4FF',
        400: '#94BDFE',
        500: '#3B82F6',
        600: '#2E69C9',
        700: '#214E98',
        800: '#0F2C5A',
        900: '#030F27',
        },
        'indigo': {
        50: '#F3F0F8',
        100: '#E7E2F1',
        200: '#D4CAE5',
        300: '#B9A9D5',
        400: '#967CBD',
        500: '#4B0082',
        600: '#3C0069',
        700: '#2B004E',
        800: '#16002C',
        900: '#05000F',
        },
      },
    },
  },
};
CSS variables
:root {
  --blue-50: #F3F8FF;
  --blue-100: #E7F1FF;
  --blue-200: #D4E5FF;
  --blue-300: #B9D4FF;
  --blue-400: #94BDFE;
  --blue-500: #3B82F6;
  --blue-600: #2E69C9;
  --blue-700: #214E98;
  --blue-800: #0F2C5A;
  --blue-900: #030F27;

  --indigo-50: #F3F0F8;
  --indigo-100: #E7E2F1;
  --indigo-200: #D4CAE5;
  --indigo-300: #B9A9D5;
  --indigo-400: #967CBD;
  --indigo-500: #4B0082;
  --indigo-600: #3C0069;
  --indigo-700: #2B004E;
  --indigo-800: #16002C;
  --indigo-900: #05000F;
}
SCSS variables
$blue-50: #F3F8FF;
$blue-100: #E7F1FF;
$blue-200: #D4E5FF;
$blue-300: #B9D4FF;
$blue-400: #94BDFE;
$blue-500: #3B82F6;
$blue-600: #2E69C9;
$blue-700: #214E98;
$blue-800: #0F2C5A;
$blue-900: #030F27;

$indigo-50: #F3F0F8;
$indigo-100: #E7E2F1;
$indigo-200: #D4CAE5;
$indigo-300: #B9A9D5;
$indigo-400: #967CBD;
$indigo-500: #4B0082;
$indigo-600: #3C0069;
$indigo-700: #2B004E;
$indigo-800: #16002C;
$indigo-900: #05000F;
JSON tokens
{
  "blue": {
    "50": "#F3F8FF",
    "100": "#E7F1FF",
    "200": "#D4E5FF",
    "300": "#B9D4FF",
    "400": "#94BDFE",
    "500": "#3B82F6",
    "600": "#2E69C9",
    "700": "#214E98",
    "800": "#0F2C5A",
    "900": "#030F27"
  },
  "indigo": {
    "50": "#F3F0F8",
    "100": "#E7E2F1",
    "200": "#D4CAE5",
    "300": "#B9A9D5",
    "400": "#967CBD",
    "500": "#4B0082",
    "600": "#3C0069",
    "700": "#2B004E",
    "800": "#16002C",
    "900": "#05000F"
  }
}

How we name colors

There is no single official authority for naming colors. We use the common, widely recognized name as the primary label for each color (here, Blue and Indigo); many common names are themselves W3C CSS named colors. For transparency we also show the nearest W3C CSS named color and the perceptual distance, ΔE, measured in OKLab. A small ΔE means the name is essentially exact; a larger one means it is the closest standard name rather than a perfect match.

Sources: W3C CSS Color Module Level 4 and the open color-name-list dataset, used to verify every color sits near a recognized name.