What color is #303FAC?

#303FAC is a medium blue. In RGB it is rgb(48, 63, 172), and in HSL hsl(233, 56%, 43%).

Is #303FAC accessible as text?

On white, #303FAC has a contrast ratio of 8.63:1 (passes WCAG AA for body text); on black it is 2.43:1 (fails). For text placed on #303FAC, use white for the best readability.

What is the closest Tailwind color to #303FAC?

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

What colors go well with #303FAC?

#303FAC pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #AB9D30. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #303FAC below.

Is #303FAC good for buttons?

#303FAC works well for buttons and highlights, but use white text on #303FAC — black text only reaches 2.43:1, below the 4.5:1 needed for normal-size labels.

Is #303FAC the same as CSS darkslateblue?

No — #303FAC is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

#303FAC Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #303FAC

Not just a swatch — here's how #303FAC works with other colors. Named schemes with #303FAC in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #303FAC 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.

Tech Product Signal · 5 colors

Signal #303FAC Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #5167CB

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 #303FAC Secondary #7F4535 Surface #EED7C2 Accent #365247 Anchor #582239

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 #303FAC Surface #F6E5D8 Anchor #5B2143 Accent #E5C2C9 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 #303FAC Secondary #69759B 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 #303FAC 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 30/100

Low

Firm and assertive — carries weight and contrast.

Depth 60/100

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 29/100

Low

A faint retro warmth without tipping into sepia.

Luxury 59/100

Moderate

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

Brand distinctiveness 47/100

Moderate

Recognisable but shares space with nearby hues.

UI accent fit 80/100

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 71/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #303FAC

For UI

For branding

For interior

For fashion

People also use #303FAC with

Carolina Blue Grape Brass Gainsboro Prussian Blue

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 8.6:1. Use

Subtle surface Use #D6D9EE for cards and hover fills. Tint 80

Avoid beside #4B30AB — 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 #303FAC 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: #303FAC;
  --color-base-rgb: 48 63 172;
  --color-base-oklch: oklch(42.8% 0.173 271.0);
  --color-50: #F3F4FC;
  --color-100: #DFE1F7;
  --color-200: #BFC5ED;
  --color-300: #939CDC;
  --color-400: #6B75C7;
  --color-500: #4955AC;
  --color-600: #3E4684;
  --color-700: #31365E;
  --color-800: #23263E;
  --color-900: #171926;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  cobalt-blue: {
    50: '#F3F4FC',
    100: '#DFE1F7',
    200: '#BFC5ED',
    300: '#939CDC',
    400: '#6B75C7',
    500: '#4955AC',
    600: '#3E4684',
    700: '#31365E',
    800: '#23263E',
    900: '#171926',
  },
}

$base: #303FAC;
$base-ink: #FFFFFF;
$base-50: #F3F4FC;
$base-100: #DFE1F7;
$base-200: #BFC5ED;
$base-300: #939CDC;
$base-400: #6B75C7;
$base-500: #4955AC;
$base-600: #3E4684;
$base-700: #31365E;
$base-800: #23263E;
$base-900: #171926;
$base-hover: #273289;
$base-subtle: #C1C5E6;

{
    "color": {
        "base": {
            "value": "#303FAC",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F3F4FC",
                "type": "color"
            },
            "100": {
                "value": "#DFE1F7",
                "type": "color"
            },
            "200": {
                "value": "#BFC5ED",
                "type": "color"
            },
            "300": {
                "value": "#939CDC",
                "type": "color"
            },
            "400": {
                "value": "#6B75C7",
                "type": "color"
            },
            "500": {
                "value": "#4955AC",
                "type": "color"
            },
            "600": {
                "value": "#3E4684",
                "type": "color"
            },
            "700": {
                "value": "#31365E",
                "type": "color"
            },
            "800": {
                "value": "#23263E",
                "type": "color"
            },
            "900": {
                "value": "#171926",
                "type": "color"
            }
        }
    }
}

Palettes built on #303FAC

Color Lab

Pairs with #303FAC

UI roles & guardrails

In real applications

Scales

Every model

Export