What color is #153FA1?

#153FA1 is a dark, vivid blue. In RGB it is rgb(21, 63, 161), and in HSL hsl(222, 77%, 36%).

Is #153FA1 accessible as text?

On white, #153FA1 has a contrast ratio of 9.30:1 (passes WCAG AA for body text); on black it is 2.26:1 (fails). For text placed on #153FA1, use white for the best readability.

What is the closest Tailwind color to #153FA1?

The nearest Tailwind CSS token is blue-900 (#1C398E).

What colors go well with #153FA1?

#153FA1 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #A27815. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #153FA1 below.

Is #153FA1 good for buttons?

#153FA1 works well for buttons and highlights, but use white text on #153FA1 — black text only reaches 2.26:1, below the 4.5:1 needed for normal-size labels.

Is #153FA1 the same as CSS darkslateblue?

No — #153FA1 is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

#153FA1 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #153FA1

Not just a swatch — here's how #153FA1 works with other colors. Named schemes with #153FA1 in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #153FA1 Accent #A5C4C1 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 #153FA1 Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #3C66C0

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 #153FA1 Secondary #7F4536 Surface #EED7C2 Accent #375246 Anchor #57223A

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 #153FA1 Surface #F6E5D8 Anchor #5B2144 Accent #E4C2CA 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 #153FA1 Secondary #5F7193 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 #153FA1 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 30/100

Low

Firm and assertive — carries weight and contrast.

Depth 62/100

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 29/100

Low

A faint retro warmth without tipping into sepia.

Luxury 61/100

High

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

Brand distinctiveness 45/100

Moderate

Recognisable but shares space with nearby hues.

UI accent fit 75/100

High

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

Surface fit 14/100

Very low

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

Print safety 69/100

High

Prints close, with a slight loss of vibrancy.

Pairs with #153FA1

For UI

For branding

For interior

For fashion

People also use #153FA1 with

Verdigris Egyptian Blue Olive Brown 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 9.3:1. Use

Subtle surface Use #CCD7F0 for cards and hover fills. Tint 80

Avoid beside #1A15A2 — 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 #153FA1 at work across the surfaces designers actually ship.

Website / UI

Northwind Sign up

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: #153FA1;
  --color-base-rgb: 21 63 161;
  --color-base-oklch: oklch(40.7% 0.165 263.3);
  --color-50: #F1F5FE;
  --color-100: #DAE4FB;
  --color-200: #B7CAF5;
  --color-300: #86A4E9;
  --color-400: #5980D9;
  --color-500: #375FBE;
  --color-600: #314E91;
  --color-700: #283B66;
  --color-800: #1E2943;
  --color-900: #141A29;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  cobalt-blue: {
    50: '#F1F5FE',
    100: '#DAE4FB',
    200: '#B7CAF5',
    300: '#86A4E9',
    400: '#5980D9',
    500: '#375FBE',
    600: '#314E91',
    700: '#283B66',
    800: '#1E2943',
    900: '#141A29',
  },
}

$base: #153FA1;
$base-ink: #FFFFFF;
$base-50: #F1F5FE;
$base-100: #DAE4FB;
$base-200: #B7CAF5;
$base-300: #86A4E9;
$base-400: #5980D9;
$base-500: #375FBE;
$base-600: #314E91;
$base-700: #283B66;
$base-800: #1E2943;
$base-900: #141A29;
$base-hover: #113382;
$base-subtle: #B1C3EB;

{
    "color": {
        "base": {
            "value": "#153FA1",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1F5FE",
                "type": "color"
            },
            "100": {
                "value": "#DAE4FB",
                "type": "color"
            },
            "200": {
                "value": "#B7CAF5",
                "type": "color"
            },
            "300": {
                "value": "#86A4E9",
                "type": "color"
            },
            "400": {
                "value": "#5980D9",
                "type": "color"
            },
            "500": {
                "value": "#375FBE",
                "type": "color"
            },
            "600": {
                "value": "#314E91",
                "type": "color"
            },
            "700": {
                "value": "#283B66",
                "type": "color"
            },
            "800": {
                "value": "#1E2943",
                "type": "color"
            },
            "900": {
                "value": "#141A29",
                "type": "color"
            }
        }
    }
}

Palettes built on #153FA1

Color Lab

Pairs with #153FA1

UI roles & guardrails

In real applications

Scales

Every model

Export