TwoColorPalette

Slate and Sky color palette

nearest CSS color: slategray · 0.04

Dashboards and SaaS marketing sites lean on this pair constantly. Slate #64748B carries the structural work, body text, borders, secondary buttons, while Sky #0EA5E9 lights up the primary action, the active link, the focus ring.

The sit only 20 degrees apart on the wheel, both cool and blue-leaning, so they read as part of one family rather than competing. between them measures 1.72 to 1, which is low. Keep that in mind: Sky on Slate (or the reverse) will not pass text contrast checks, so use each against white or a near-white background, not against each other.

If you blend them, you land on a muted blue (#4F8DB9) that works well for hover states or chart fills.

See Slate and Sky in use

Background ⇄ tap a mockup to swap colors
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Slate Tailwind scale (50-900)

Sky Tailwind scale (50-900)

Slate to Sky blend

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

Why Slate and Sky 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 Slate text on Sky (or the reverse) for body copy. For readable text, pair a dark scale step such as slate-800 or sky-900 with a light one like sky-50.

Contrast pairing grid

Rows are Slate steps, columns are Sky steps. Each mark is a Slate step shown on a Sky 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-slate-50: #F5F6F8;
  --color-slate-100: #EBEDF1;
  --color-slate-200: #DBDFE5;
  --color-slate-300: #C4CBD4;
  --color-slate-400: #A7B0BE;
  --color-slate-500: #64748B;
  --color-slate-600: #505E71;
  --color-slate-700: #3B4554;
  --color-slate-800: #20262F;
  --color-slate-900: #090C11;

  --color-sky-50: #F4FAFE;
  --color-sky-100: #E8F5FD;
  --color-sky-200: #D5ECFC;
  --color-sky-300: #B9E0F9;
  --color-sky-400: #93CFF5;
  --color-sky-500: #0EA5E9;
  --color-sky-600: #0986BF;
  --color-sky-700: #056590;
  --color-sky-800: #023A55;
  --color-sky-900: #001624;
}
Tailwind v3 — tailwind.config.js
// tailwind.config.js
module.exports = {
  theme: {
    extend: {
      colors: {
        'slate': {
        50: '#F5F6F8',
        100: '#EBEDF1',
        200: '#DBDFE5',
        300: '#C4CBD4',
        400: '#A7B0BE',
        500: '#64748B',
        600: '#505E71',
        700: '#3B4554',
        800: '#20262F',
        900: '#090C11',
        },
        'sky': {
        50: '#F4FAFE',
        100: '#E8F5FD',
        200: '#D5ECFC',
        300: '#B9E0F9',
        400: '#93CFF5',
        500: '#0EA5E9',
        600: '#0986BF',
        700: '#056590',
        800: '#023A55',
        900: '#001624',
        },
      },
    },
  },
};
CSS variables
:root {
  --slate-50: #F5F6F8;
  --slate-100: #EBEDF1;
  --slate-200: #DBDFE5;
  --slate-300: #C4CBD4;
  --slate-400: #A7B0BE;
  --slate-500: #64748B;
  --slate-600: #505E71;
  --slate-700: #3B4554;
  --slate-800: #20262F;
  --slate-900: #090C11;

  --sky-50: #F4FAFE;
  --sky-100: #E8F5FD;
  --sky-200: #D5ECFC;
  --sky-300: #B9E0F9;
  --sky-400: #93CFF5;
  --sky-500: #0EA5E9;
  --sky-600: #0986BF;
  --sky-700: #056590;
  --sky-800: #023A55;
  --sky-900: #001624;
}
SCSS variables
$slate-50: #F5F6F8;
$slate-100: #EBEDF1;
$slate-200: #DBDFE5;
$slate-300: #C4CBD4;
$slate-400: #A7B0BE;
$slate-500: #64748B;
$slate-600: #505E71;
$slate-700: #3B4554;
$slate-800: #20262F;
$slate-900: #090C11;

$sky-50: #F4FAFE;
$sky-100: #E8F5FD;
$sky-200: #D5ECFC;
$sky-300: #B9E0F9;
$sky-400: #93CFF5;
$sky-500: #0EA5E9;
$sky-600: #0986BF;
$sky-700: #056590;
$sky-800: #023A55;
$sky-900: #001624;
JSON tokens
{
  "slate": {
    "50": "#F5F6F8",
    "100": "#EBEDF1",
    "200": "#DBDFE5",
    "300": "#C4CBD4",
    "400": "#A7B0BE",
    "500": "#64748B",
    "600": "#505E71",
    "700": "#3B4554",
    "800": "#20262F",
    "900": "#090C11"
  },
  "sky": {
    "50": "#F4FAFE",
    "100": "#E8F5FD",
    "200": "#D5ECFC",
    "300": "#B9E0F9",
    "400": "#93CFF5",
    "500": "#0EA5E9",
    "600": "#0986BF",
    "700": "#056590",
    "800": "#023A55",
    "900": "#001624"
  }
}

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, Slate and Sky); 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.