What color is #331ADB?

#331ADB is a medium, vivid indigo. In RGB it is rgb(51, 26, 219), and in HSL hsl(248, 79%, 48%).

Is #331ADB accessible as text?

On white, #331ADB has a contrast ratio of 9.09:1 (passes WCAG AA for body text); on black it is 2.31:1 (fails). For text placed on #331ADB, use white for the best readability.

What is the closest Tailwind color to #331ADB?

The nearest Tailwind CSS token is indigo-700 (#432DD7).

What colors go well with #331ADB?

#331ADB pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #C1DB1A. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #331ADB below.

Is #331ADB good for buttons?

#331ADB works well for buttons and highlights, but use white text on #331ADB — black text only reaches 2.31:1, below the 4.5:1 needed for normal-size labels.

Is #331ADB the same as CSS mediumblue?

No — #331ADB is not the CSS named color mediumblue, but mediumblue (#0000CD) is the closest CSS named color.

#331ADB Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #331ADB

Not just a swatch — here's how #331ADB works with other colors. Named schemes with #331ADB in its natural role, and a note on why the supporting colors balance it.

Tech Product Signal · 5 colors

Signal #331ADB Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #4C58F8

Ultramarine is the vivid signal in this product UI — on a near-black surface with cool white, a slate grey and a lighter tint of Ultramarine.

Coastal Morning Lead · 5 colors

Lead #331ADB Accent #A5C4C2 Surface #EAD5C0 Secondary #9AA0A1 Anchor #21344A

Ultramarine 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 #331ADB Surface #F6E5D8 Anchor #5B2143 Accent #E5C2C9 Secondary #322B2F

Ultramarine 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 #331ADB Secondary #6674AE Support #9D8F88 Ink #18140F

Ultramarine 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 Ultramarine carrying the quiet middle.

Sunset Warmth Glow · 5 colors

Glow #331ADB Secondary #E86A73 Accent #F6924F Anchor #573B58 Surface #F7E7D7

Ultramarine 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 #331ADB 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 13/100

Cool

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

Softness 22/100

Low

Firm and assertive — carries weight and contrast.

Depth 63/100

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 4/100

Very low

Clean and current — no dusty, aged cast.

Luxury 52/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 100/100

Very high

Bold and ownable — memorable as a primary brand color.

UI accent fit 48/100

Moderate

Workable accent with care around contrast.

Surface fit 12/100

Very low

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

Print safety 57/100

Moderate

Prints close, with a slight loss of vibrancy.

Pairs with #331ADB

For UI

For branding

For interior

For fashion

People also use #331ADB with

Signal Blue Dark Violet Yellow Green 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 9.1:1. Use

Subtle surface Use #D9D5F4 for cards and hover fills. Tint 80

Avoid beside #741ADB — 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 #331ADB 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: #331ADB;
  --color-base-rgb: 51 26 219;
  --color-base-oklch: oklch(43.3% 0.260 272.7);
  --color-50: #F2F1FE;
  --color-100: #DEDAFC;
  --color-200: #BFB6F6;
  --color-300: #9285EB;
  --color-400: #6958DA;
  --color-500: #4735C0;
  --color-600: #3D3092;
  --color-700: #302867;
  --color-800: #231D43;
  --color-900: #171429;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  ultramarine: {
    50: '#F2F1FE',
    100: '#DEDAFC',
    200: '#BFB6F6',
    300: '#9285EB',
    400: '#6958DA',
    500: '#4735C0',
    600: '#3D3092',
    700: '#302867',
    800: '#231D43',
    900: '#171429',
  },
}

$base: #331ADB;
$base-ink: #FFFFFF;
$base-50: #F2F1FE;
$base-100: #DEDAFC;
$base-200: #BFB6F6;
$base-300: #9285EB;
$base-400: #6958DA;
$base-500: #4735C0;
$base-600: #3D3092;
$base-700: #302867;
$base-800: #231D43;
$base-900: #171429;
$base-hover: #2915AF;
$base-subtle: #C6BFEF;

{
    "color": {
        "base": {
            "value": "#331ADB",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F2F1FE",
                "type": "color"
            },
            "100": {
                "value": "#DEDAFC",
                "type": "color"
            },
            "200": {
                "value": "#BFB6F6",
                "type": "color"
            },
            "300": {
                "value": "#9285EB",
                "type": "color"
            },
            "400": {
                "value": "#6958DA",
                "type": "color"
            },
            "500": {
                "value": "#4735C0",
                "type": "color"
            },
            "600": {
                "value": "#3D3092",
                "type": "color"
            },
            "700": {
                "value": "#302867",
                "type": "color"
            },
            "800": {
                "value": "#231D43",
                "type": "color"
            },
            "900": {
                "value": "#171429",
                "type": "color"
            }
        }
    }
}

Palettes built on #331ADB

Color Lab

Pairs with #331ADB

UI roles & guardrails

In real applications

Scales

Every model

Export