What color is #040309?

#040309 is a very dark low-chroma blue-gray with a subtle blue cast. In RGB it is rgb(4, 3, 9), and in HSL hsl(250, 50%, 2%).

Is #040309 accessible as text?

On white, #040309 has a contrast ratio of 20.55:1 (passes WCAG AA for body text); on black it is 1.02:1 (fails). For text placed on #040309, use white for the best readability.

What is the closest Tailwind color to #040309?

The nearest Tailwind CSS token is gray-950 (#030712).

What colors go well with #040309?

As a neutral, #040309 pairs cleanly with white, off-white and light grays for text, and sits under accent hues like blue, violet, emerald or warm orange — use it as a dark surface or high-contrast base and let the accent carry the color.

Is #040309 the same as CSS black?

No — #040309 is not the CSS named color black, but black (#000000) is the closest CSS named color.

#040309 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #040309

Not just a swatch — here's how #040309 works with other colors. Named schemes with #040309 in its natural role, and a note on why the supporting colors balance it.

Tech Product Signal · 5 colors

Signal #040309 Surface #14161A Highlight #F4F6F8 Secondary #5B6572 Accent #1C1A23

Jet Black is the vivid signal in this product UI — on a near-black surface with cool white, a slate grey and a lighter tint of Jet Black.

Vintage Leather Lead · 5 colors

Lead #040309 Secondary #7E4632 Surface #EDD8C2 Accent #355248 Anchor #582237

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.

Japanese Sand Base · 5 colors

Base #040309 Surface #F2E8DD Highlight #F8F0E7 Secondary #BEADA1 Ink #2C2724

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.

Berry & Cream Lead · 5 colors

Lead #040309 Surface #F5E5D7 Anchor #5C2141 Accent #E5C2C8 Secondary #332B2F

Jet Black sits between cream and a deep berry here, softened by a blush accent and grounded by charcoal.

Minimal Editorial Surface · 5 colors

Surface #F8F4EF Accent #040309 Secondary #202024 Support #9D9088 Ink #18140F

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 #040309 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 47/100

Neutral

Balanced temperature — flexible, sits between warm and cool schemes.

Softness 13/100

Very low

Firm and assertive — carries weight and contrast.

Depth 84/100

Very high

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

Naturalness 0/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 15/100

Very low

Clean and current — no dusty, aged cast.

Luxury 81/100

Very high

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

Brand distinctiveness 8/100

Very low

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

UI accent fit 2/100

Very low

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

Surface fit 72/100

High

Calm enough for large fills — backgrounds, cards, sections.

Print safety 97/100

Very high

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #040309

For UI

For branding

For interior

For fashion

People also use #040309 with

Graphite Jet Black Gainsboro Prussian Blue

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 20.5:1. Use

Subtle surface Use #C1BBDF for cards and hover fills. Tint 80

Avoid beside #050308 — 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 #040309 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: #040309;
  --color-base-rgb: 4 3 9;
  --color-base-oklch: oklch(10.5% 0.020 292.8);
  --color-50: #F5F3FC;
  --color-100: #E3E0F5;
  --color-200: #C9C2EB;
  --color-300: #A297D8;
  --color-400: #7D70C2;
  --color-500: #5D4EA6;
  --color-600: #4C4280;
  --color-700: #3A335C;
  --color-800: #28243C;
  --color-900: #1A1825;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  jet-black: {
    50: '#F5F3FC',
    100: '#E3E0F5',
    200: '#C9C2EB',
    300: '#A297D8',
    400: '#7D70C2',
    500: '#5D4EA6',
    600: '#4C4280',
    700: '#3A335C',
    800: '#28243C',
    900: '#1A1825',
  },
}

$base: #040309;
$base-ink: #FFFFFF;
$base-50: #F5F3FC;
$base-100: #E3E0F5;
$base-200: #C9C2EB;
$base-300: #A297D8;
$base-400: #7D70C2;
$base-500: #5D4EA6;
$base-600: #4C4280;
$base-700: #3A335C;
$base-800: #28243C;
$base-900: #1A1825;
$base-hover: #030206;
$base-subtle: #A198D1;

{
    "color": {
        "base": {
            "value": "#040309",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F5F3FC",
                "type": "color"
            },
            "100": {
                "value": "#E3E0F5",
                "type": "color"
            },
            "200": {
                "value": "#C9C2EB",
                "type": "color"
            },
            "300": {
                "value": "#A297D8",
                "type": "color"
            },
            "400": {
                "value": "#7D70C2",
                "type": "color"
            },
            "500": {
                "value": "#5D4EA6",
                "type": "color"
            },
            "600": {
                "value": "#4C4280",
                "type": "color"
            },
            "700": {
                "value": "#3A335C",
                "type": "color"
            },
            "800": {
                "value": "#28243C",
                "type": "color"
            },
            "900": {
                "value": "#1A1825",
                "type": "color"
            }
        }
    }
}

Palettes built on #040309

Color Lab

Pairs with #040309

UI roles & guardrails

In real applications

Scales

Every model

Export