What color is #243EB4?

#243EB4 is a medium blue. In RGB it is rgb(36, 62, 180), and in HSL hsl(229, 67%, 42%).

Is #243EB4 accessible as text?

On white, #243EB4 has a contrast ratio of 8.67:1 (passes WCAG AA for body text); on black it is 2.42:1 (fails). For text placed on #243EB4, use white for the best readability.

What is the closest Tailwind color to #243EB4?

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

What colors go well with #243EB4?

#243EB4 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #B39923. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #243EB4 below.

Is #243EB4 good for buttons?

#243EB4 works well for buttons and highlights, but use white text on #243EB4 — black text only reaches 2.42:1, below the 4.5:1 needed for normal-size labels.

Is #243EB4 the same as CSS darkslateblue?

No — #243EB4 is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

#243EB4 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #243EB4

Not just a swatch — here's how #243EB4 works with other colors. Named schemes with #243EB4 in its natural role, and a note on why the supporting colors balance it.

Tech Product Signal · 5 colors

Signal #243EB4 Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #4667D2

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.

Coastal Morning Lead · 5 colors

Lead #243EB4 Accent #A5C4C2 Surface #EAD5C0 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.

Berry & Cream Lead · 5 colors

Lead #243EB4 Surface #F6E5D8 Anchor #5B2143 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 #243EB4 Secondary #66769E 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.

Sunset Warmth Glow · 5 colors

Glow #243EB4 Secondary #E86A74 Accent #F79250 Anchor #573B58 Surface #F7E7D7

Cobalt Blue glows at the center of this sunset palette, joined by coral and gold, deepened by a plum anchor and cooled with cream.

Build a working theme in the generator →

Color Lab

How #243EB4 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 10/100

Cool

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

Softness 29/100

Low

Firm and assertive — carries weight and contrast.

Depth 61/100

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 24/100

Low

Clean and current — no dusty, aged cast.

Luxury 58/100

Moderate

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

Brand distinctiveness 73/100

High

Bold and ownable — memorable as a primary brand color.

UI accent fit 76/100

High

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

Surface fit 12/100

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 #243EB4

For UI

For branding

For interior

For fashion

People also use #243EB4 with

Carolina Blue Grape Dijon Gainsboro Gunmetal Gray

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 8.7:1. Use

Subtle surface Use #D3D8F0 for cards and hover fills. Tint 80

Avoid beside #3923B3 — 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 #243EB4 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: #243EB4;
  --color-base-rgb: 36 62 180;
  --color-base-oklch: oklch(42.8% 0.188 267.5);
  --color-50: #F2F4FD;
  --color-100: #DCE1F9;
  --color-200: #BBC5F1;
  --color-300: #8C9CE3;
  --color-400: #6276D0;
  --color-500: #3F55B5;
  --color-600: #37468B;
  --color-700: #2C3662;
  --color-800: #202641;
  --color-900: #161928;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  cobalt-blue: {
    50: '#F2F4FD',
    100: '#DCE1F9',
    200: '#BBC5F1',
    300: '#8C9CE3',
    400: '#6276D0',
    500: '#3F55B5',
    600: '#37468B',
    700: '#2C3662',
    800: '#202641',
    900: '#161928',
  },
}

$base: #243EB4;
$base-ink: #FFFFFF;
$base-50: #F2F4FD;
$base-100: #DCE1F9;
$base-200: #BBC5F1;
$base-300: #8C9CE3;
$base-400: #6276D0;
$base-500: #3F55B5;
$base-600: #37468B;
$base-700: #2C3662;
$base-800: #202641;
$base-900: #161928;
$base-hover: #1C318F;
$base-subtle: #BCC4E9;

{
    "color": {
        "base": {
            "value": "#243EB4",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F2F4FD",
                "type": "color"
            },
            "100": {
                "value": "#DCE1F9",
                "type": "color"
            },
            "200": {
                "value": "#BBC5F1",
                "type": "color"
            },
            "300": {
                "value": "#8C9CE3",
                "type": "color"
            },
            "400": {
                "value": "#6276D0",
                "type": "color"
            },
            "500": {
                "value": "#3F55B5",
                "type": "color"
            },
            "600": {
                "value": "#37468B",
                "type": "color"
            },
            "700": {
                "value": "#2C3662",
                "type": "color"
            },
            "800": {
                "value": "#202641",
                "type": "color"
            },
            "900": {
                "value": "#161928",
                "type": "color"
            }
        }
    }
}

Palettes built on #243EB4

Color Lab

Pairs with #243EB4

UI roles & guardrails

In real applications

Scales

Every model

Export