What color is #18599E?

#18599E is a dark, vivid blue. In RGB it is rgb(24, 89, 158), and in HSL hsl(211, 74%, 36%).

Is #18599E accessible as text?

On white, #18599E has a contrast ratio of 7.09:1 (passes WCAG AA for body text); on black it is 2.96:1 (fails). For text placed on #18599E, use white for the best readability.

What is the closest Tailwind color to #18599E?

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

What colors go well with #18599E?

#18599E pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #A05E18. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #18599E below.

Is #18599E good for buttons?

#18599E works well for buttons and highlights, but use white text on #18599E — black text only reaches 2.96:1, below the 4.5:1 needed for normal-size labels.

Is #18599E the same as CSS darkslateblue?

No — #18599E is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

#18599E Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #18599E

Not just a swatch — here's how #18599E works with other colors. Named schemes with #18599E in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #18599E Accent #A5C4C1 Surface #DDDBBF Secondary #9AA0A1 Anchor #20344A

Lapis Lazuli 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 #18599E Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #467DBE

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

Vintage Leather Lead · 5 colors

Lead #18599E Secondary #7F4537 Surface #E1DDC1 Accent #375246 Anchor #57233B

Lapis Lazuli 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 #18599E Surface #EDE9D6 Anchor #5A2145 Accent #E4C2CB Secondary #322B2F

Lapis Lazuli sits between cream and a deep berry here, softened by a blush accent and grounded by charcoal.

Minimal Editorial Surface · 5 colors

Surface #F6F4EF Accent #18599E Secondary #6F839C Support #9D8F89 Ink #16140F

Lapis Lazuli 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 Lapis Lazuli carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #18599E 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 15/100

Cool

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

Softness 37/100

Low

Middle-weight — neither delicate nor heavy.

Depth 55/100

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 42/100

Moderate

A faint retro warmth without tipping into sepia.

Luxury 60/100

Moderate

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

Brand distinctiveness 35/100

Low

Recognisable but shares space with nearby hues.

UI accent fit 92/100

Very high

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

Surface fit 16/100

Very low

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

Print safety 73/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #18599E

For UI

For branding

For interior

For fashion

People also use #18599E with

Tiffany Blue Zaffre Sienna 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 7.1:1. Use

Subtle surface Use #CDDEF0 for cards and hover fills. Tint 80

Avoid beside #182CA0 — 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 #18599E at work across the surfaces designers actually ship.

Website / UI

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Build faster.

A working theme, generated in seconds.

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: #18599E;
  --color-base-rgb: 24 89 158;
  --color-base-oklch: oklch(46.3% 0.129 253.7);
  --color-50: #F1F7FE;
  --color-100: #DBEAFB;
  --color-200: #B8D5F4;
  --color-300: #88B6E7;
  --color-400: #5C97D6;
  --color-500: #3978BC;
  --color-600: #335F8F;
  --color-700: #2A4665;
  --color-800: #1F3042;
  --color-900: #151E29;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  lapis-lazuli: {
    50: '#F1F7FE',
    100: '#DBEAFB',
    200: '#B8D5F4',
    300: '#88B6E7',
    400: '#5C97D6',
    500: '#3978BC',
    600: '#335F8F',
    700: '#2A4665',
    800: '#1F3042',
    900: '#151E29',
  },
}

$base: #18599E;
$base-ink: #FFFFFF;
$base-50: #F1F7FE;
$base-100: #DBEAFB;
$base-200: #B8D5F4;
$base-300: #88B6E7;
$base-400: #5C97D6;
$base-500: #3978BC;
$base-600: #335F8F;
$base-700: #2A4665;
$base-800: #1F3042;
$base-900: #151E29;
$base-hover: #134880;
$base-subtle: #B3CDEA;

{
    "color": {
        "base": {
            "value": "#18599E",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1F7FE",
                "type": "color"
            },
            "100": {
                "value": "#DBEAFB",
                "type": "color"
            },
            "200": {
                "value": "#B8D5F4",
                "type": "color"
            },
            "300": {
                "value": "#88B6E7",
                "type": "color"
            },
            "400": {
                "value": "#5C97D6",
                "type": "color"
            },
            "500": {
                "value": "#3978BC",
                "type": "color"
            },
            "600": {
                "value": "#335F8F",
                "type": "color"
            },
            "700": {
                "value": "#2A4665",
                "type": "color"
            },
            "800": {
                "value": "#1F3042",
                "type": "color"
            },
            "900": {
                "value": "#151E29",
                "type": "color"
            }
        }
    }
}

Palettes built on #18599E

Color Lab

Pairs with #18599E

UI roles & guardrails

In real applications

Scales

Every model

Export