What color is #183DAD?

#183DAD is a dark, vivid blue. In RGB it is rgb(24, 61, 173), and in HSL hsl(225, 76%, 39%).

Is #183DAD accessible as text?

On white, #183DAD has a contrast ratio of 9.09:1 (passes WCAG AA for body text); on black it is 2.31:1 (fails). For text placed on #183DAD, use white for the best readability.

What is the closest Tailwind color to #183DAD?

The nearest Tailwind CSS token is blue-800 (#193CB8).

What colors go well with #183DAD?

#183DAD pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #AF8918. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #183DAD below.

Is #183DAD good for buttons?

#183DAD works well for buttons and highlights, but use white text on #183DAD — black text only reaches 2.31:1, below the 4.5:1 needed for normal-size labels.

Is #183DAD the same as CSS darkslateblue?

No — #183DAD is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

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

Palettes built on #183DAD

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

Coastal Morning Lead · 5 colors

Lead #183DAD Accent #A5C4C2 Surface #DDDBBF Secondary #9AA0A1 Anchor #21344A

Cobalt 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 #183DAD Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #3D65CB

Cobalt 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 Cobalt Blue.

Vintage Leather Lead · 5 colors

Lead #183DAD Secondary #7F4536 Surface #EED7C2 Accent #365246 Anchor #58223A

Cobalt 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 #183DAD Surface #F6E5D8 Anchor #5B2144 Accent #E5C2CA Secondary #322B2F

Cobalt 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 #183DAD Secondary #617399 Support #9D8F88 Ink #18140F

Cobalt 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 Cobalt Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #183DAD 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 9/100

Cool

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

Softness 28/100

Low

Firm and assertive — carries weight and contrast.

Depth 62/100

High

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

Naturalness 0/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 25/100

Low

Clean and current — no dusty, aged cast.

Luxury 59/100

Moderate

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

Brand distinctiveness 50/100

Moderate

Recognisable but shares space with nearby hues.

UI accent fit 74/100

High

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

Surface fit 13/100

Very low

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

Print safety 67/100

High

Prints close, with a slight loss of vibrancy.

Pairs with #183DAD

For UI

For branding

For interior

For fashion

People also use #183DAD with

Picton Blue Egyptian Blue Dark Goldenrod 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 9.1:1. Use

Subtle surface Use #CFD7F1 for cards and hover fills. Tint 80

Avoid beside #2418AF — 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 #183DAD 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: #183DAD;
  --color-base-rgb: 24 61 173;
  --color-base-oklch: oklch(41.5% 0.183 264.9);
  --color-50: #F1F4FE;
  --color-100: #DAE2FB;
  --color-200: #B7C7F5;
  --color-300: #879FE9;
  --color-400: #5A7AD8;
  --color-500: #3759BD;
  --color-600: #324990;
  --color-700: #293866;
  --color-800: #1E2743;
  --color-900: #141929;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  cobalt-blue: {
    50: '#F1F4FE',
    100: '#DAE2FB',
    200: '#B7C7F5',
    300: '#879FE9',
    400: '#5A7AD8',
    500: '#3759BD',
    600: '#324990',
    700: '#293866',
    800: '#1E2743',
    900: '#141929',
  },
}

$base: #183DAD;
$base-ink: #FFFFFF;
$base-50: #F1F4FE;
$base-100: #DAE2FB;
$base-200: #B7C7F5;
$base-300: #879FE9;
$base-400: #5A7AD8;
$base-500: #3759BD;
$base-600: #324990;
$base-700: #293866;
$base-800: #1E2743;
$base-900: #141929;
$base-hover: #13318C;
$base-subtle: #B5C3EB;

{
    "color": {
        "base": {
            "value": "#183DAD",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1F4FE",
                "type": "color"
            },
            "100": {
                "value": "#DAE2FB",
                "type": "color"
            },
            "200": {
                "value": "#B7C7F5",
                "type": "color"
            },
            "300": {
                "value": "#879FE9",
                "type": "color"
            },
            "400": {
                "value": "#5A7AD8",
                "type": "color"
            },
            "500": {
                "value": "#3759BD",
                "type": "color"
            },
            "600": {
                "value": "#324990",
                "type": "color"
            },
            "700": {
                "value": "#293866",
                "type": "color"
            },
            "800": {
                "value": "#1E2743",
                "type": "color"
            },
            "900": {
                "value": "#141929",
                "type": "color"
            }
        }
    }
}

Palettes built on #183DAD

Color Lab

Pairs with #183DAD

UI roles & guardrails

In real applications

Scales

Every model

Export