What color is #243F90?

#243F90 is a dark blue. In RGB it is rgb(36, 63, 144), and in HSL hsl(225, 60%, 35%).

Is #243F90 accessible as text?

On white, #243F90 has a contrast ratio of 9.59:1 (passes WCAG AA for body text); on black it is 2.19:1 (fails). For text placed on #243F90, use white for the best readability.

What is the closest Tailwind color to #243F90?

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

What colors go well with #243F90?

#243F90 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #8F7424. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #243F90 below.

Is #243F90 good for buttons?

#243F90 works well for buttons and highlights, but use white text on #243F90 — black text only reaches 2.19:1, below the 4.5:1 needed for normal-size labels.

Is #243F90 the same as CSS darkslateblue?

No — #243F90 is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

#243F90 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #243F90

Not just a swatch — here's how #243F90 works with other colors. Named schemes with #243F90 in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #243F90 Accent #A5C4C2 Surface #EAD5C0 Secondary #9AA0A1 Anchor #21344A

Classic 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 #243F90 Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #4764AF

Classic 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 Classic Blue.

Vintage Leather Lead · 5 colors

Lead #243F90 Secondary #7F4536 Surface #EED7C2 Accent #365246 Anchor #58223A

Classic 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 #243F90 Surface #F6E5D8 Anchor #5B2144 Accent #E5C2CA Secondary #322B2F

Classic 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 #243F90 Secondary #616E8B Support #9D8F88 Ink #18140F

Classic 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 Classic Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #243F90 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 17/100

Cool

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

Softness 31/100

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 36/100

Low

A faint retro warmth without tipping into sepia.

Luxury 64/100

High

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

Brand distinctiveness 37/100

Low

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 17/100

Very low

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

Print safety 75/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #243F90

For UI

For branding

For interior

For fashion

People also use #243F90 with

Bondi Blue Indigo 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 9.6:1. Use

Subtle surface Use #D0D7EC for cards and hover fills. Tint 80

Avoid beside #2D248F — 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 #243F90 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: #243F90;
  --color-base-rgb: 36 63 144;
  --color-base-oklch: oklch(39.7% 0.138 266.2);
  --color-50: #F2F5FC;
  --color-100: #DEE4F8;
  --color-200: #BECAEF;
  --color-300: #91A4DE;
  --color-400: #6780CB;
  --color-500: #4660AF;
  --color-600: #3C4E86;
  --color-700: #2F3B60;
  --color-800: #22293F;
  --color-900: #161B27;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  classic-blue: {
    50: '#F2F5FC',
    100: '#DEE4F8',
    200: '#BECAEF',
    300: '#91A4DE',
    400: '#6780CB',
    500: '#4660AF',
    600: '#3C4E86',
    700: '#2F3B60',
    800: '#22293F',
    900: '#161B27',
  },
}

$base: #243F90;
$base-ink: #FFFFFF;
$base-50: #F2F5FC;
$base-100: #DEE4F8;
$base-200: #BECAEF;
$base-300: #91A4DE;
$base-400: #6780CB;
$base-500: #4660AF;
$base-600: #3C4E86;
$base-700: #2F3B60;
$base-800: #22293F;
$base-900: #161B27;
$base-hover: #1D3272;
$base-subtle: #B7C2E4;

{
    "color": {
        "base": {
            "value": "#243F90",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F2F5FC",
                "type": "color"
            },
            "100": {
                "value": "#DEE4F8",
                "type": "color"
            },
            "200": {
                "value": "#BECAEF",
                "type": "color"
            },
            "300": {
                "value": "#91A4DE",
                "type": "color"
            },
            "400": {
                "value": "#6780CB",
                "type": "color"
            },
            "500": {
                "value": "#4660AF",
                "type": "color"
            },
            "600": {
                "value": "#3C4E86",
                "type": "color"
            },
            "700": {
                "value": "#2F3B60",
                "type": "color"
            },
            "800": {
                "value": "#22293F",
                "type": "color"
            },
            "900": {
                "value": "#161B27",
                "type": "color"
            }
        }
    }
}

Palettes built on #243F90

Color Lab

Pairs with #243F90

UI roles & guardrails

In real applications

Scales

Every model

Export