What color is #331CE3?

#331CE3 is a medium, vivid indigo. In RGB it is rgb(51, 28, 227), and in HSL hsl(247, 78%, 50%).

Is #331CE3 accessible as text?

On white, #331CE3 has a contrast ratio of 8.69:1 (passes WCAG AA for body text); on black it is 2.42:1 (fails). For text placed on #331CE3, use white for the best readability.

What is the closest Tailwind color to #331CE3?

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

What colors go well with #331CE3?

#331CE3 pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #CCE31C. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #331CE3 below.

Is #331CE3 good for buttons?

#331CE3 works well for buttons and highlights, but use white text on #331CE3 — black text only reaches 2.42:1, below the 4.5:1 needed for normal-size labels.

Is #331CE3 the same as CSS blue?

No — #331CE3 is not the CSS named color blue, but blue (#0000FF) is the closest CSS named color.

#331CE3 Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #331CE3

Not just a swatch — here's how #331CE3 works with other colors. Named schemes with #331CE3 in its natural role, and a note on why the supporting colors balance it.

Tech Product Signal · 5 colors

Signal #331CE3 Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #4C5BFF

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 #331CE3 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 #331CE3 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 #331CE3 Secondary #6878B3 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 #331CE3 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 #331CE3 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 62/100

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 2/100

Very low

Clean and current — no dusty, aged cast.

Luxury 50/100

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 46/100

Moderate

Workable accent with care around contrast.

Surface fit 11/100

Very low

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

Print safety 55/100

Moderate

Prints close, with a slight loss of vibrancy.

Pairs with #331CE3

For UI

For branding

For interior

For fashion

People also use #331CE3 with

Dodger Blue Dark Orchid Pear 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 #DBD7F4 for cards and hover fills. Tint 80

Avoid beside #761CE3 — 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 #331CE3 at work across the surfaces designers actually ship.

Website / UI

Northwind Sign up

Build faster.

A working theme, generated in seconds.

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: #331CE3;
  --color-base-rgb: 51 28 227;
  --color-base-oklch: oklch(44.4% 0.267 272.0);
  --color-50: #F2F1FE;
  --color-100: #DEDAFB;
  --color-200: #BEB6F6;
  --color-300: #9185EA;
  --color-400: #6758DA;
  --color-500: #4636BF;
  --color-600: #3C3091;
  --color-700: #2F2867;
  --color-800: #221E43;
  --color-900: #171429;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  ultramarine: {
    50: '#F2F1FE',
    100: '#DEDAFB',
    200: '#BEB6F6',
    300: '#9185EA',
    400: '#6758DA',
    500: '#4636BF',
    600: '#3C3091',
    700: '#2F2867',
    800: '#221E43',
    900: '#171429',
  },
}

$base: #331CE3;
$base-ink: #FFFFFF;
$base-50: #F2F1FE;
$base-100: #DEDAFB;
$base-200: #BEB6F6;
$base-300: #9185EA;
$base-400: #6758DA;
$base-500: #4636BF;
$base-600: #3C3091;
$base-700: #2F2867;
$base-800: #221E43;
$base-900: #171429;
$base-hover: #2916B6;
$base-subtle: #C7C2EF;

{
    "color": {
        "base": {
            "value": "#331CE3",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F2F1FE",
                "type": "color"
            },
            "100": {
                "value": "#DEDAFB",
                "type": "color"
            },
            "200": {
                "value": "#BEB6F6",
                "type": "color"
            },
            "300": {
                "value": "#9185EA",
                "type": "color"
            },
            "400": {
                "value": "#6758DA",
                "type": "color"
            },
            "500": {
                "value": "#4636BF",
                "type": "color"
            },
            "600": {
                "value": "#3C3091",
                "type": "color"
            },
            "700": {
                "value": "#2F2867",
                "type": "color"
            },
            "800": {
                "value": "#221E43",
                "type": "color"
            },
            "900": {
                "value": "#171429",
                "type": "color"
            }
        }
    }
}

Palettes built on #331CE3

Color Lab

Pairs with #331CE3

UI roles & guardrails

In real applications

Scales

Every model

Export