What color is #210308?

#210308 is a very dark, vivid red. In RGB it is rgb(33, 3, 8), and in HSL hsl(350, 83%, 7%).

Is #210308 accessible as text?

On white, #210308 has a contrast ratio of 19.42:1 (passes WCAG AA for body text); on black it is 1.08:1 (fails). For text placed on #210308, use white for the best readability.

What is the closest Tailwind color to #210308?

The nearest Tailwind CSS token is mauve-950 (#0C090C).

What colors go well with #210308?

#210308 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #03211C. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #210308 below.

Is #210308 good for buttons?

#210308 works well for buttons and highlights, but use white text on #210308 — black text only reaches 1.08:1, below the 4.5:1 needed for normal-size labels.

Is #210308 the same as CSS black?

No — #210308 is not the CSS named color black, but black (#000000) is the closest CSS named color.

#210308 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #210308

Not just a swatch — here's how #210308 works with other colors. Named schemes with #210308 in its natural role, and a note on why the supporting colors balance it.

Vintage Leather Lead · 5 colors

Lead #210308 Secondary #7C4829 Surface #EBD9C1 Accent #444F39 Anchor #5A222F

Jet Black plays the worn-leather lead, deepened by saddle brown and an oxblood anchor, softened by aged cream and cooled by a muted forest green.

Warm Autumn Interior Dominant · 5 colors

Dominant #210308 Secondary #B86229 Accent #797642 Surface #F5EBDD Anchor #3B2A21

This palette keeps Jet Black as the dominant warm neutral, balanced by muted terracotta and olive earth tones and grounded by a deep espresso anchor.

Japanese Sand Base · 5 colors

Base #210308 Surface #F0E8DC Highlight #F7F1E7 Secondary #BBAEA0 Ink #2B2723

Jet Black sets a calm, sun-bleached base here, wrapped in bone and paper off-whites and a soft greige, with a single ink accent for wabi-sabi restraint.

Luxury Packaging Feature · 5 colors

Feature #210308 Anchor #141210 Accent #D29D4F Secondary #322526 Surface #F3EDE3

Jet Black carries the depth in this luxury scheme, offset by a brass accent and near-black and held together by a deep neutral and an off-white surface.

Minimal Editorial Surface · 5 colors

Surface #F7F4EF Accent #210308 Secondary #382C2D Support #9B9087 Ink #17140F

Jet Black is the single accent in this high-contrast editorial system — set on near-white paper against near-black ink, with a warm grey and a desaturated tint of Jet Black carrying the quiet middle.

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Color Lab

How #210308 actually behaves in design work — read from its OKLCH lightness, chroma and hue, not just its raw numbers. Ten signals to help you decide where this color earns its place.

Warmth 63/100

Warm

Reads warm and advancing — inviting, energetic, draws the eye forward.

Softness 18/100

Very low

Firm and assertive — carries weight and contrast.

Depth 80/100

Very high

Deep and grounding — anchors a layout, strong dark-mode base.

Naturalness 38/100

Low

Loosely natural — an earthy edge without being rustic.

Vintage feel 33/100

Low

A faint retro warmth without tipping into sepia.

Luxury 80/100

Very high

Restrained and premium — deep, quiet, high-end packaging and fashion.

Brand distinctiveness 21/100

Low

Quiet and neutral — a supporting tone, not a signature.

UI accent fit 8/100

Very low

Weak as an action color — too pale, too dark or too muted to signal.

Surface fit 58/100

Moderate

Usable as a tinted surface in measured doses.

Print safety 94/100

Very high

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #210308

For UI

For branding

For interior

For fashion

People also use #210308 with

Deep Purple Graphite Gainsboro Taupe

UI roles & guardrails

Primary action Safe as a filled button with white label. AAA

Body text Passes on white at 16px and above. Pass

Large display Fine for headings 24px+ on white. Pass

Background Pair with white text at 19.4:1. Use

Subtle surface Use #ECB3BD for cards and hover fills. Tint 80

Avoid beside #210803 — the hue gap is too small to read as intentional. Clash

In real applications

Not a swatch to memorise — a color to build with. Here is #210308 at work across the surfaces designers actually ship.

Website / UI

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Dashboard

Revenue

$48.2k ▲ 12%

Brand

AVELINE

Studio

Poster

Nov 14 · 8PM

NIGHT
MARKET

Packaging

BLOOM

Botanical Wash

250 ml

Interior

Every model

Export

:root {
  --color-base: #210308;
  --color-base-rgb: 33 3 8;
  --color-base-oklch: oklch(16.6% 0.055 12.6);
  --color-50: #FEF0F3;
  --color-100: #FDD9DF;
  --color-200: #F8B4C0;
  --color-300: #ED8294;
  --color-400: #DE546B;
  --color-500: #C3314A;
  --color-600: #952D3E;
  --color-700: #692631;
  --color-800: #441C23;
  --color-900: #2A1317;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  jet-black: {
    50: '#FEF0F3',
    100: '#FDD9DF',
    200: '#F8B4C0',
    300: '#ED8294',
    400: '#DE546B',
    500: '#C3314A',
    600: '#952D3E',
    700: '#692631',
    800: '#441C23',
    900: '#2A1317',
  },
}

$base: #210308;
$base-ink: #FFFFFF;
$base-50: #FEF0F3;
$base-100: #FDD9DF;
$base-200: #F8B4C0;
$base-300: #ED8294;
$base-400: #DE546B;
$base-500: #C3314A;
$base-600: #952D3E;
$base-700: #692631;
$base-800: #441C23;
$base-900: #2A1317;
$base-hover: #1A0206;
$base-subtle: #E58B9A;

{
    "color": {
        "base": {
            "value": "#210308",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#FEF0F3",
                "type": "color"
            },
            "100": {
                "value": "#FDD9DF",
                "type": "color"
            },
            "200": {
                "value": "#F8B4C0",
                "type": "color"
            },
            "300": {
                "value": "#ED8294",
                "type": "color"
            },
            "400": {
                "value": "#DE546B",
                "type": "color"
            },
            "500": {
                "value": "#C3314A",
                "type": "color"
            },
            "600": {
                "value": "#952D3E",
                "type": "color"
            },
            "700": {
                "value": "#692631",
                "type": "color"
            },
            "800": {
                "value": "#441C23",
                "type": "color"
            },
            "900": {
                "value": "#2A1317",
                "type": "color"
            }
        }
    }
}

Palettes built on #210308

Color Lab

Pairs with #210308

UI roles & guardrails

In real applications

Scales

Every model

Export