What color is #2B37DA?

#2B37DA is a medium, vivid blue. In RGB it is rgb(43, 55, 218), and in HSL hsl(236, 70%, 51%).

Is #2B37DA accessible as text?

On white, #2B37DA has a contrast ratio of 7.89:1 (passes WCAG AA for body text); on black it is 2.66:1 (fails). For text placed on #2B37DA, use white for the best readability.

What is the closest Tailwind color to #2B37DA?

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

What colors go well with #2B37DA?

#2B37DA pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #DACE2B. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #2B37DA below.

Is #2B37DA good for buttons?

#2B37DA works well for buttons and highlights, but use white text on #2B37DA — black text only reaches 2.66:1, below the 4.5:1 needed for normal-size labels.

Is #2B37DA the same as CSS blue?

No — #2B37DA is not the CSS named color blue, but blue (#0000FF) is the closest CSS named color.

#2B37DA Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #2B37DA

Not just a swatch — here's how #2B37DA works with other colors. Named schemes with #2B37DA in its natural role, and a note on why the supporting colors balance it.

Tech Product Signal · 5 colors

Signal #2B37DA Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #4968F7

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 #2B37DA 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 #2B37DA 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 #2B37DA Secondary #6B7DB2 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 #2B37DA Secondary #E86A74 Accent #F69250 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 #2B37DA 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 11/100

Cool

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

Softness 25/100

Low

Firm and assertive — carries weight and contrast.

Depth 60/100

Moderate

Mid depth — usable as an accent or a muted ground.

Naturalness 0/100

Very low

Reads engineered rather than organic — synthetic, digital.

Vintage feel 10/100

Very low

Clean and current — no dusty, aged cast.

Luxury 51/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 93/100

Very high

Bold and ownable — memorable as a primary brand color.

UI accent fit 61/100

High

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

Surface fit 10/100

Very low

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

Print safety 58/100

Moderate

Prints close, with a slight loss of vibrancy.

Pairs with #2B37DA

For UI

For branding

For interior

For fashion

People also use #2B37DA with

Picton Blue Blue Violet Citrine 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 7.9:1. Use

Subtle surface Use #D9DBF3 for cards and hover fills. Tint 80

Avoid beside #592BDA — 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 #2B37DA 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: #2B37DA;
  --color-base-rgb: 43 55 218;
  --color-base-oklch: oklch(45.8% 0.240 269.3);
  --color-50: #F1F2FD;
  --color-100: #DBDEFA;
  --color-200: #BABEF3;
  --color-300: #8A90E5;
  --color-400: #5F67D3;
  --color-500: #3D45B8;
  --color-600: #353B8C;
  --color-700: #2B2F64;
  --color-800: #202241;
  --color-900: #151628;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  ultramarine: {
    50: '#F1F2FD',
    100: '#DBDEFA',
    200: '#BABEF3',
    300: '#8A90E5',
    400: '#5F67D3',
    500: '#3D45B8',
    600: '#353B8C',
    700: '#2B2F64',
    800: '#202241',
    900: '#151628',
  },
}

$base: #2B37DA;
$base-ink: #FFFFFF;
$base-50: #F1F2FD;
$base-100: #DBDEFA;
$base-200: #BABEF3;
$base-300: #8A90E5;
$base-400: #5F67D3;
$base-500: #3D45B8;
$base-600: #353B8C;
$base-700: #2B2F64;
$base-800: #202241;
$base-900: #151628;
$base-hover: #1F29B1;
$base-subtle: #C6C8ED;

{
    "color": {
        "base": {
            "value": "#2B37DA",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1F2FD",
                "type": "color"
            },
            "100": {
                "value": "#DBDEFA",
                "type": "color"
            },
            "200": {
                "value": "#BABEF3",
                "type": "color"
            },
            "300": {
                "value": "#8A90E5",
                "type": "color"
            },
            "400": {
                "value": "#5F67D3",
                "type": "color"
            },
            "500": {
                "value": "#3D45B8",
                "type": "color"
            },
            "600": {
                "value": "#353B8C",
                "type": "color"
            },
            "700": {
                "value": "#2B2F64",
                "type": "color"
            },
            "800": {
                "value": "#202241",
                "type": "color"
            },
            "900": {
                "value": "#151628",
                "type": "color"
            }
        }
    }
}

Palettes built on #2B37DA

Color Lab

Pairs with #2B37DA

UI roles & guardrails

In real applications

Scales

Every model

Export