What color is #3939B4?

#3939B4 is a medium blue-violet. In RGB it is rgb(57, 57, 180), and in HSL hsl(240, 52%, 46%).

Is #3939B4 accessible as text?

On white, #3939B4 has a contrast ratio of 8.68:1 (passes WCAG AA for body text); on black it is 2.42:1 (fails). For text placed on #3939B4, use white for the best readability.

What is the closest Tailwind color to #3939B4?

The nearest Tailwind CSS token is indigo-800 (#372AAC).

What colors go well with #3939B4?

#3939B4 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #B2B238. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #3939B4 below.

Is #3939B4 good for buttons?

#3939B4 works well for buttons and highlights, but use white text on #3939B4 — black text only reaches 2.42:1, below the 4.5:1 needed for normal-size labels.

Is #3939B4 the same as CSS darkslateblue?

No — #3939B4 is not the CSS named color darkslateblue, but darkslateblue (#483D8B) is the closest CSS named color.

#3939B4 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #3939B4

Not just a swatch — here's how #3939B4 works with other colors. Named schemes with #3939B4 in its natural role, and a note on why the supporting colors balance it.

Tech Product Signal · 5 colors

Signal #3939B4 Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #5863D2

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.

Berry & Cream Lead · 5 colors

Lead #3939B4 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 #3939B4 Secondary #6C759F Support #9D9088 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.

Coastal Morning Lead · 5 colors

Lead #3939B4 Accent #A5C4C2 Surface #EAD5BF 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.

Sunset Warmth Glow · 5 colors

Glow #3939B4 Secondary #E86A72 Accent #F6924E 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 #3939B4 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 15/100

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 25/100

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 77/100

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 70/100

High

Prints close, with a slight loss of vibrancy.

Pairs with #3939B4

For UI

For branding

For interior

For fashion

People also use #3939B4 with

Ocean 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 8.7:1. Use

Subtle surface Use #D9D9EE for cards and hover fills. Tint 80

Avoid beside #6138B2 — 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 #3939B4 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: #3939B4;
  --color-base-rgb: 57 57 180;
  --color-base-oklch: oklch(43.0% 0.189 275.0);
  --color-50: #F3F3FC;
  --color-100: #DFDFF6;
  --color-200: #C1C1EB;
  --color-300: #9696D9;
  --color-400: #6E6EC4;
  --color-500: #4D4DA8;
  --color-600: #414181;
  --color-700: #32325C;
  --color-800: #24243D;
  --color-900: #181826;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  cobalt-blue: {
    50: '#F3F3FC',
    100: '#DFDFF6',
    200: '#C1C1EB',
    300: '#9696D9',
    400: '#6E6EC4',
    500: '#4D4DA8',
    600: '#414181',
    700: '#32325C',
    800: '#24243D',
    900: '#181826',
  },
}

$base: #3939B4;
$base-ink: #FFFFFF;
$base-50: #F3F3FC;
$base-100: #DFDFF6;
$base-200: #C1C1EB;
$base-300: #9696D9;
$base-400: #6E6EC4;
$base-500: #4D4DA8;
$base-600: #414181;
$base-700: #32325C;
$base-800: #24243D;
$base-900: #181826;
$base-hover: #2D2D8F;
$base-subtle: #C5C5E6;

{
    "color": {
        "base": {
            "value": "#3939B4",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F3F3FC",
                "type": "color"
            },
            "100": {
                "value": "#DFDFF6",
                "type": "color"
            },
            "200": {
                "value": "#C1C1EB",
                "type": "color"
            },
            "300": {
                "value": "#9696D9",
                "type": "color"
            },
            "400": {
                "value": "#6E6EC4",
                "type": "color"
            },
            "500": {
                "value": "#4D4DA8",
                "type": "color"
            },
            "600": {
                "value": "#414181",
                "type": "color"
            },
            "700": {
                "value": "#32325C",
                "type": "color"
            },
            "800": {
                "value": "#24243D",
                "type": "color"
            },
            "900": {
                "value": "#181826",
                "type": "color"
            }
        }
    }
}

Palettes built on #3939B4

Color Lab

Pairs with #3939B4

UI roles & guardrails

In real applications

Scales

Every model

Export