What color is #042F3B?

#042F3B is a very dark, vivid cyan. In RGB it is rgb(4, 47, 59), and in HSL hsl(193, 87%, 12%).

Is #042F3B accessible as text?

On white, #042F3B has a contrast ratio of 14.24:1 (passes WCAG AA for body text); on black it is 1.47:1 (fails). For text placed on #042F3B, use white for the best readability.

What is the closest Tailwind color to #042F3B?

The nearest Tailwind CSS token is cyan-950 (#053345).

What colors go well with #042F3B?

#042F3B pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #391004. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #042F3B below.

Is #042F3B good for buttons?

#042F3B works well for buttons and highlights, but use white text on #042F3B — black text only reaches 1.47:1, below the 4.5:1 needed for normal-size labels.

Is #042F3B the same as CSS midnightblue?

No — #042F3B is not the CSS named color midnightblue, but midnightblue (#191970) is the closest CSS named color.

#042F3B Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #042F3B

Not just a swatch — here's how #042F3B works with other colors. Named schemes with #042F3B in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #042F3B Accent #A6C4BF Surface #DFDABF Secondary #9AA0A0 Anchor #1E354A

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 #042F3B Secondary #AEB4B8 Surface #F1F2F0 Support #7B93A5 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 #042F3B Surface #14161A Highlight #F4F6F8 Secondary #596672 Accent #2C4E5A

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 #042F3B Secondary #705116 Surface #E2DCC0 Accent #385244 Anchor #56233E

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 #042F3B Secondary #445055 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 #042F3B 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 36/100

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 1/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 28/100

Low

A faint retro warmth without tipping into sepia.

Luxury 71/100

High

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

Brand distinctiveness 19/100

Very low

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

UI accent fit 25/100

Low

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

Surface fit 52/100

Moderate

Usable as a tinted surface in measured doses.

Print safety 87/100

Very high

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #042F3B

For UI

For branding

For interior

For fashion

People also use #042F3B with

Hunter Green Navy Oxblood Platinum Dark Slate Gray

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 14.2:1. Use

Subtle surface Use #B6E2EE for cards and hover fills. Tint 80

Avoid beside #041C39 — 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 #042F3B 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: #042F3B;
  --color-base-rgb: 4 47 59;
  --color-base-oklch: oklch(28.4% 0.049 221.6);
  --color-50: #F0FBFE;
  --color-100: #D8F5FD;
  --color-200: #B3EAFA;
  --color-300: #7FD7F0;
  --color-400: #51C2E1;
  --color-500: #2EA6C7;
  --color-600: #2B8097;
  --color-700: #245B6B;
  --color-800: #1C3C45;
  --color-900: #13252A;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  prussian-blue: {
    50: '#F0FBFE',
    100: '#D8F5FD',
    200: '#B3EAFA',
    300: '#7FD7F0',
    400: '#51C2E1',
    500: '#2EA6C7',
    600: '#2B8097',
    700: '#245B6B',
    800: '#1C3C45',
    900: '#13252A',
  },
}

$base: #042F3B;
$base-ink: #FFFFFF;
$base-50: #F0FBFE;
$base-100: #D8F5FD;
$base-200: #B3EAFA;
$base-300: #7FD7F0;
$base-400: #51C2E1;
$base-500: #2EA6C7;
$base-600: #2B8097;
$base-700: #245B6B;
$base-800: #1C3C45;
$base-900: #13252A;
$base-hover: #03252E;
$base-subtle: #8FD5E8;

{
    "color": {
        "base": {
            "value": "#042F3B",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F0FBFE",
                "type": "color"
            },
            "100": {
                "value": "#D8F5FD",
                "type": "color"
            },
            "200": {
                "value": "#B3EAFA",
                "type": "color"
            },
            "300": {
                "value": "#7FD7F0",
                "type": "color"
            },
            "400": {
                "value": "#51C2E1",
                "type": "color"
            },
            "500": {
                "value": "#2EA6C7",
                "type": "color"
            },
            "600": {
                "value": "#2B8097",
                "type": "color"
            },
            "700": {
                "value": "#245B6B",
                "type": "color"
            },
            "800": {
                "value": "#1C3C45",
                "type": "color"
            },
            "900": {
                "value": "#13252A",
                "type": "color"
            }
        }
    }
}