What color is #183D4E?

#183D4E is a dark cyan-blue. In RGB it is rgb(24, 61, 78), and in HSL hsl(199, 53%, 20%).

Is #183D4E accessible as text?

On white, #183D4E has a contrast ratio of 11.56:1 (passes WCAG AA for body text); on black it is 1.82:1 (fails). For text placed on #183D4E, use white for the best readability.

What is the closest Tailwind color to #183D4E?

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

What colors go well with #183D4E?

#183D4E pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #4E2918. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #183D4E below.

Is #183D4E good for buttons?

#183D4E works well for buttons and highlights, but use white text on #183D4E — black text only reaches 1.82:1, below the 4.5:1 needed for normal-size labels.

Is #183D4E the same as CSS darkslategray?

No — #183D4E is not the CSS named color darkslategray, but darkslategray (#2F4F4F) is the closest CSS named color.

#183D4E Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #183D4E

Not just a swatch — here's how #183D4E works with other colors. Named schemes with #183D4E in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #183D4E Accent #A6C4BF Surface #DEDABF Secondary #9AA0A0 Anchor #1F344A

Gunmetal Gray 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 #183D4E Secondary #AEB4B8 Surface #F1F2F0 Support #7B93A6 Anchor #2E3236

Gunmetal Gray 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 #183D4E Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #3D5D6E

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

Vintage Leather Lead · 5 colors

Lead #183D4E Secondary #6F5216 Surface #E2DCC0 Accent #385244 Anchor #56233D

Gunmetal Gray 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 #183D4E Secondary #546066 Support #969386 Ink #16140F

Gunmetal Gray 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 Gunmetal Gray carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #183D4E 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 35/100

Cool

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

Softness 34/100

Low

Middle-weight — neither delicate nor heavy.

Depth 63/100

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 33/100

Low

A faint retro warmth without tipping into sepia.

Luxury 66/100

High

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

Brand distinctiveness 20/100

Very low

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

UI accent fit 39/100

Low

Workable accent with care around contrast.

Surface fit 47/100

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 #183D4E

For UI

For branding

For interior

For fashion

People also use #183D4E with

Pine Green Navy Bistre Platinum 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 11.6:1. Use

Subtle surface Use #C7DCE6 for cards and hover fills. Tint 80

Avoid beside #182B4E — 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 #183D4E 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: #183D4E;
  --color-base-rgb: 24 61 78;
  --color-base-oklch: oklch(34.1% 0.051 230.8);
  --color-50: #F3F9FC;
  --color-100: #DFEFF6;
  --color-200: #C1DEEC;
  --color-300: #95C4DA;
  --color-400: #6DA9C5;
  --color-500: #4C8CA9;
  --color-600: #406D82;
  --color-700: #324F5D;
  --color-800: #24353D;
  --color-900: #172126;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  gunmetal-gray: {
    50: '#F3F9FC',
    100: '#DFEFF6',
    200: '#C1DEEC',
    300: '#95C4DA',
    400: '#6DA9C5',
    500: '#4C8CA9',
    600: '#406D82',
    700: '#324F5D',
    800: '#24353D',
    900: '#172126',
  },
}

$base: #183D4E;
$base-ink: #FFFFFF;
$base-50: #F3F9FC;
$base-100: #DFEFF6;
$base-200: #C1DEEC;
$base-300: #95C4DA;
$base-400: #6DA9C5;
$base-500: #4C8CA9;
$base-600: #406D82;
$base-700: #324F5D;
$base-800: #24353D;
$base-900: #172126;
$base-hover: #13313E;
$base-subtle: #A9CBDA;

{
    "color": {
        "base": {
            "value": "#183D4E",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F3F9FC",
                "type": "color"
            },
            "100": {
                "value": "#DFEFF6",
                "type": "color"
            },
            "200": {
                "value": "#C1DEEC",
                "type": "color"
            },
            "300": {
                "value": "#95C4DA",
                "type": "color"
            },
            "400": {
                "value": "#6DA9C5",
                "type": "color"
            },
            "500": {
                "value": "#4C8CA9",
                "type": "color"
            },
            "600": {
                "value": "#406D82",
                "type": "color"
            },
            "700": {
                "value": "#324F5D",
                "type": "color"
            },
            "800": {
                "value": "#24353D",
                "type": "color"
            },
            "900": {
                "value": "#172126",
                "type": "color"
            }
        }
    }
}