What color is #042F4E?

#042F4E is a very dark, vivid cyan-blue. In RGB it is rgb(4, 47, 78), and in HSL hsl(205, 90%, 16%).

Is #042F4E accessible as text?

On white, #042F4E has a contrast ratio of 13.80:1 (passes WCAG AA for body text); on black it is 1.52:1 (fails). For text placed on #042F4E, use white for the best readability.

What is the closest Tailwind color to #042F4E?

The nearest Tailwind CSS token is sky-950 (#052F4A).

What colors go well with #042F4E?

#042F4E pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #4E2304. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #042F4E below.

Is #042F4E good for buttons?

#042F4E works well for buttons and highlights, but use white text on #042F4E — black text only reaches 1.52:1, below the 4.5:1 needed for normal-size labels.

Is #042F4E the same as CSS midnightblue?

No — #042F4E is not the CSS named color midnightblue, but midnightblue (#191970) is the closest CSS named color.

#042F4E Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #042F4E

Not just a swatch — here's how #042F4E works with other colors. Named schemes with #042F4E in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #042F4E Accent #A5C4C0 Surface #DDDBBF Secondary #9AA0A1 Anchor #20344A

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

Nordic Calm Accent · 5 colors

Accent #042F4E Secondary #AEB4B8 Surface #F1F2F0 Support #7C93A6 Anchor #2E3236

Prussian Blue keeps this Nordic scheme quiet — cool greys and a soft white around it, a muted-blue support and a charcoal anchor.

Tech Product Signal · 5 colors

Signal #042F4E Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #2C4F6D

Prussian 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 Prussian Blue.

Vintage Leather Lead · 5 colors

Lead #042F4E Secondary #7F4438 Surface #E1DDC0 Accent #375245 Anchor #57233C

Prussian 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.

Minimal Editorial Surface · 5 colors

Surface #F6F4EF Accent #042F4E Secondary #46535F Support #969386 Ink #16140F

Prussian 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 Prussian Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #042F4E 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 30/100

Cool

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

Softness 29/100

Low

Firm and assertive — carries weight and contrast.

Depth 69/100

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 34/100

Low

A faint retro warmth without tipping into sepia.

Luxury 72/100

High

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

Brand distinctiveness 28/100

Low

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

UI accent fit 32/100

Low

Workable accent with care around contrast.

Surface fit 44/100

Moderate

Usable as a tinted surface in measured doses.

Print safety 84/100

Very high

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #042F4E

For UI

For branding

For interior

For fashion

People also use #042F4E with

Pine Green Navy Bistre 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 13.8:1. Use

Subtle surface Use #B8D9F0 for cards and hover fills. Tint 80

Avoid beside #04164E — 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 #042F4E 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: #042F4E;
  --color-base-rgb: 4 47 78;
  --color-base-oklch: oklch(29.6% 0.072 246.0);
  --color-50: #F0F9FE;
  --color-100: #D8EEFD;
  --color-200: #B2DCFB;
  --color-300: #7EC1F2;
  --color-400: #4FA5E3;
  --color-500: #2B88CA;
  --color-600: #296A99;
  --color-700: #234D6C;
  --color-800: #1B3446;
  --color-900: #12212B;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  prussian-blue: {
    50: '#F0F9FE',
    100: '#D8EEFD',
    200: '#B2DCFB',
    300: '#7EC1F2',
    400: '#4FA5E3',
    500: '#2B88CA',
    600: '#296A99',
    700: '#234D6C',
    800: '#1B3446',
    900: '#12212B',
  },
}

$base: #042F4E;
$base-ink: #FFFFFF;
$base-50: #F0F9FE;
$base-100: #D8EEFD;
$base-200: #B2DCFB;
$base-300: #7EC1F2;
$base-400: #4FA5E3;
$base-500: #2B88CA;
$base-600: #296A99;
$base-700: #234D6C;
$base-800: #1B3446;
$base-900: #12212B;
$base-hover: #03263E;
$base-subtle: #93C6EB;

{
    "color": {
        "base": {
            "value": "#042F4E",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F0F9FE",
                "type": "color"
            },
            "100": {
                "value": "#D8EEFD",
                "type": "color"
            },
            "200": {
                "value": "#B2DCFB",
                "type": "color"
            },
            "300": {
                "value": "#7EC1F2",
                "type": "color"
            },
            "400": {
                "value": "#4FA5E3",
                "type": "color"
            },
            "500": {
                "value": "#2B88CA",
                "type": "color"
            },
            "600": {
                "value": "#296A99",
                "type": "color"
            },
            "700": {
                "value": "#234D6C",
                "type": "color"
            },
            "800": {
                "value": "#1B3446",
                "type": "color"
            },
            "900": {
                "value": "#12212B",
                "type": "color"
            }
        }
    }
}