What color is #1B5CAB?

#1B5CAB is a dark, vivid blue. In RGB it is rgb(27, 92, 171), and in HSL hsl(213, 73%, 39%).

Is #1B5CAB accessible as text?

On white, #1B5CAB has a contrast ratio of 6.63:1 (passes WCAG AA for body text); on black it is 3.17:1 (fails). For text placed on #1B5CAB, use white for the best readability.

What is the closest Tailwind color to #1B5CAB?

The nearest Tailwind CSS token is sky-700 (#0069A8).

What colors go well with #1B5CAB?

#1B5CAB pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #AC6B1B. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #1B5CAB below.

Is #1B5CAB good for buttons?

#1B5CAB works well for buttons and highlights, but use white text on #1B5CAB — black text only reaches 3.17:1, below the 4.5:1 needed for normal-size labels.

Is #1B5CAB the same as CSS darkslateblue?

No — #1B5CAB is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

#1B5CAB Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #1B5CAB

Not just a swatch — here's how #1B5CAB works with other colors. Named schemes with #1B5CAB in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #1B5CAB Accent #A5C4C1 Surface #DDDBBF Secondary #9AA0A1 Anchor #20344A

Denim 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 #1B5CAB Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #4981CB

Denim 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 Denim Blue.

Vintage Leather Lead · 5 colors

Lead #1B5CAB Secondary #7F4537 Surface #E1DDC1 Accent #375246 Anchor #57233B

Denim 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 #1B5CAB Surface #EDE9D6 Anchor #5A2145 Accent #E4C2CA Secondary #322B2F

Denim Blue 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 #1B5CAB Secondary #7388A4 Support #9D8F89 Ink #16140F

Denim 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 Denim Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #1B5CAB 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 12/100

Cool

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

Softness 37/100

Low

Middle-weight — neither delicate nor heavy.

Depth 53/100

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 40/100

Low

A faint retro warmth without tipping into sepia.

Luxury 57/100

Moderate

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

Brand distinctiveness 38/100

Low

Recognisable but shares space with nearby hues.

UI accent fit 96/100

Very high

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

Surface fit 11/100

Very low

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

Print safety 71/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #1B5CAB

For UI

For branding

For interior

For fashion

People also use #1B5CAB with

Dark Turquoise Klein Blue Ginger Gainsboro Charcoal

UI roles & guardrails

Primary action Safe as a filled button with white label. AA

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 6.6:1. Use

Subtle surface Use #D0DEF0 for cards and hover fills. Tint 80

Avoid beside #1B2CAC — 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 #1B5CAB 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: #1B5CAB;
  --color-base-rgb: 27 92 171;
  --color-base-oklch: oklch(47.9% 0.142 256.0);
  --color-50: #F1F7FD;
  --color-100: #DBE9FA;
  --color-200: #B9D3F4;
  --color-300: #88B3E7;
  --color-400: #5D93D5;
  --color-500: #3A74BB;
  --color-600: #335C8E;
  --color-700: #2A4465;
  --color-800: #1F2F42;
  --color-900: #151E28;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  denim-blue: {
    50: '#F1F7FD',
    100: '#DBE9FA',
    200: '#B9D3F4',
    300: '#88B3E7',
    400: '#5D93D5',
    500: '#3A74BB',
    600: '#335C8E',
    700: '#2A4465',
    800: '#1F2F42',
    900: '#151E28',
  },
}

$base: #1B5CAB;
$base-ink: #FFFFFF;
$base-50: #F1F7FD;
$base-100: #DBE9FA;
$base-200: #B9D3F4;
$base-300: #88B3E7;
$base-400: #5D93D5;
$base-500: #3A74BB;
$base-600: #335C8E;
$base-700: #2A4465;
$base-800: #1F2F42;
$base-900: #151E28;
$base-hover: #154A8A;
$base-subtle: #B6CEEA;

{
    "color": {
        "base": {
            "value": "#1B5CAB",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1F7FD",
                "type": "color"
            },
            "100": {
                "value": "#DBE9FA",
                "type": "color"
            },
            "200": {
                "value": "#B9D3F4",
                "type": "color"
            },
            "300": {
                "value": "#88B3E7",
                "type": "color"
            },
            "400": {
                "value": "#5D93D5",
                "type": "color"
            },
            "500": {
                "value": "#3A74BB",
                "type": "color"
            },
            "600": {
                "value": "#335C8E",
                "type": "color"
            },
            "700": {
                "value": "#2A4465",
                "type": "color"
            },
            "800": {
                "value": "#1F2F42",
                "type": "color"
            },
            "900": {
                "value": "#151E28",
                "type": "color"
            }
        }
    }
}