TwoColorPalette

Red and Blue color palette

nearest CSS color: dodgerblue · 0.036

Reds and blues this saturated carry the same visual weight, so the pairing reads as a clash of equals rather than one color leading. The sit 125 degrees apart for a strong warm-cool split, but near-identical lightness (a 1.02 to 1 ratio) keeps either from receding.

That energy suits branding and posters, including sports identities, political graphics, and bold editorial covers. On the web, separate them with white or a dark neutral, since red text on blue (or the reverse) will vibrate and fail accessibility checks. For a bridging tone, their midpoint is a muted purple (#A775A5).

See Red and Blue in use

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Red Tailwind scale (50-900)

Blue Tailwind scale (50-900)

Red to Blue blend

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

Why Red and Blue 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 Red text on Blue (or the reverse) for body copy. For readable text, pair a dark scale step such as red-800 or blue-900 with a light one like blue-50.

Contrast pairing grid

Rows are Red steps, columns are Blue steps. Each mark is a Red step shown on a Blue 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-red-50: #FFF5F4;
  --color-red-100: #FFEBE8;
  --color-red-200: #FFDAD5;
  --color-red-300: #FFC2BB;
  --color-red-400: #FFA098;
  --color-red-500: #EF4444;
  --color-red-600: #C43636;
  --color-red-700: #942626;
  --color-red-800: #571313;
  --color-red-900: #260404;

  --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;
}
Tailwind v3 — tailwind.config.js
// tailwind.config.js
module.exports = {
  theme: {
    extend: {
      colors: {
        'red': {
        50: '#FFF5F4',
        100: '#FFEBE8',
        200: '#FFDAD5',
        300: '#FFC2BB',
        400: '#FFA098',
        500: '#EF4444',
        600: '#C43636',
        700: '#942626',
        800: '#571313',
        900: '#260404',
        },
        'blue': {
        50: '#F3F8FF',
        100: '#E7F1FF',
        200: '#D4E5FF',
        300: '#B9D4FF',
        400: '#94BDFE',
        500: '#3B82F6',
        600: '#2E69C9',
        700: '#214E98',
        800: '#0F2C5A',
        900: '#030F27',
        },
      },
    },
  },
};
CSS variables
:root {
  --red-50: #FFF5F4;
  --red-100: #FFEBE8;
  --red-200: #FFDAD5;
  --red-300: #FFC2BB;
  --red-400: #FFA098;
  --red-500: #EF4444;
  --red-600: #C43636;
  --red-700: #942626;
  --red-800: #571313;
  --red-900: #260404;

  --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;
}
SCSS variables
$red-50: #FFF5F4;
$red-100: #FFEBE8;
$red-200: #FFDAD5;
$red-300: #FFC2BB;
$red-400: #FFA098;
$red-500: #EF4444;
$red-600: #C43636;
$red-700: #942626;
$red-800: #571313;
$red-900: #260404;

$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;
JSON tokens
{
  "red": {
    "50": "#FFF5F4",
    "100": "#FFEBE8",
    "200": "#FFDAD5",
    "300": "#FFC2BB",
    "400": "#FFA098",
    "500": "#EF4444",
    "600": "#C43636",
    "700": "#942626",
    "800": "#571313",
    "900": "#260404"
  },
  "blue": {
    "50": "#F3F8FF",
    "100": "#E7F1FF",
    "200": "#D4E5FF",
    "300": "#B9D4FF",
    "400": "#94BDFE",
    "500": "#3B82F6",
    "600": "#2E69C9",
    "700": "#214E98",
    "800": "#0F2C5A",
    "900": "#030F27"
  }
}

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, Red and Blue); 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.