What color is #304E8A?

#304E8A is a dark blue. In RGB it is rgb(48, 78, 138), and in HSL hsl(220, 48%, 36%).

Is #304E8A accessible as text?

On white, #304E8A has a contrast ratio of 8.13:1 (passes WCAG AA for body text); on black it is 2.58:1 (fails). For text placed on #304E8A, use white for the best readability.

What is the closest Tailwind color to #304E8A?

The nearest Tailwind CSS token is sky-800 (#00598A).

What colors go well with #304E8A?

#304E8A pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #886A30. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #304E8A below.

Is #304E8A good for buttons?

#304E8A works well for buttons and highlights, but use white text on #304E8A — black text only reaches 2.58:1, below the 4.5:1 needed for normal-size labels.

Is #304E8A the same as CSS darkslateblue?

No — #304E8A is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

#304E8A Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #304E8A

Not just a swatch — here's how #304E8A works with other colors. Named schemes with #304E8A in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #304E8A Accent #A5C4C1 Surface #DDDBBF Secondary #9AA0A1 Anchor #21344A

Classic Blue opens this coastal palette with sea-glass and warm sand alongside it, grounded by driftwood grey and a deep-navy anchor.

Tech Product Signal · 5 colors

Signal #304E8A Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #5471AA

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

Vintage Leather Lead · 5 colors

Lead #304E8A Secondary #7F4536 Surface #E1DDC1 Accent #375246 Anchor #57223A

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

Berry & Cream Lead · 5 colors

Lead #304E8A Surface #F6E5D8 Anchor #5A2144 Accent #E4C2CA Secondary #322B2F

Classic Blue 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 #304E8A Secondary #6D788F Support #9D8F88 Ink #18140F

Classic Blue 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 Classic Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #304E8A 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 24/100

Cool

Reads cool and recessive — calming, technical, good for trust-led UI.

Softness 37/100

Low

Middle-weight — neither delicate nor heavy.

Depth 57/100

Moderate

Mid depth — usable as an accent or a muted ground.

Naturalness 0/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 47/100

Moderate

A faint retro warmth without tipping into sepia.

Luxury 63/100

High

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

Brand distinctiveness 29/100

Low

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

UI accent fit 81/100

Very high

Strong interactive accent — visible and can carry a legible label.

Surface fit 25/100

Low

Too saturated or mid-toned for big areas — keep it to accents.

Print safety 80/100

Very high

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #304E8A

For UI

For branding

For interior

For fashion

People also use #304E8A with

Cadet Blue Dark Slate Blue Olive Brown Gainsboro Charcoal

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 8.1:1. Use

Subtle surface Use #D3DBEA for cards and hover fills. Tint 80

Avoid beside #303088 — 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 #304E8A at work across the surfaces designers actually ship.

Website / UI

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Build faster.

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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: #304E8A;
  --color-base-rgb: 48 78 138;
  --color-base-oklch: oklch(43.2% 0.106 262.7);
  --color-50: #F3F6FB;
  --color-100: #E0E7F5;
  --color-200: #C3D0EA;
  --color-300: #99ADD7;
  --color-400: #718CC1;
  --color-500: #506CA5;
  --color-600: #43577F;
  --color-700: #34415B;
  --color-800: #252D3C;
  --color-900: #181C25;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  classic-blue: {
    50: '#F3F6FB',
    100: '#E0E7F5',
    200: '#C3D0EA',
    300: '#99ADD7',
    400: '#718CC1',
    500: '#506CA5',
    600: '#43577F',
    700: '#34415B',
    800: '#252D3C',
    900: '#181C25',
  },
}

$base: #304E8A;
$base-ink: #FFFFFF;
$base-50: #F3F6FB;
$base-100: #E0E7F5;
$base-200: #C3D0EA;
$base-300: #99ADD7;
$base-400: #718CC1;
$base-500: #506CA5;
$base-600: #43577F;
$base-700: #34415B;
$base-800: #252D3C;
$base-900: #181C25;
$base-hover: #263E6D;
$base-subtle: #BCC8E0;

{
    "color": {
        "base": {
            "value": "#304E8A",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F3F6FB",
                "type": "color"
            },
            "100": {
                "value": "#E0E7F5",
                "type": "color"
            },
            "200": {
                "value": "#C3D0EA",
                "type": "color"
            },
            "300": {
                "value": "#99ADD7",
                "type": "color"
            },
            "400": {
                "value": "#718CC1",
                "type": "color"
            },
            "500": {
                "value": "#506CA5",
                "type": "color"
            },
            "600": {
                "value": "#43577F",
                "type": "color"
            },
            "700": {
                "value": "#34415B",
                "type": "color"
            },
            "800": {
                "value": "#252D3C",
                "type": "color"
            },
            "900": {
                "value": "#181C25",
                "type": "color"
            }
        }
    }
}