What color is #577CEB?

#577CEB is a light, vivid blue. In RGB it is rgb(87, 124, 235), and in HSL hsl(225, 79%, 63%).

Is #577CEB accessible as text?

On white, #577CEB has a contrast ratio of 3.83:1 (fails WCAG AA for body text); on black it is 5.49:1 (passes). For text placed on #577CEB, use black for the best readability.

What is the closest Tailwind color to #577CEB?

The nearest Tailwind CSS token is blue-500 (#2B7FFF).

What colors go well with #577CEB?

#577CEB pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #EBC656. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #577CEB below.

Is #577CEB good for buttons?

#577CEB works well for buttons and highlights, but use black text on #577CEB — white text only reaches 3.83:1, below the 4.5:1 needed for normal-size labels.

Is #577CEB the same as CSS royalblue?

No — #577CEB is not the CSS named color royalblue, but royalblue (#4169E1) is the closest CSS named color.

#577CEB Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #577CEB

Not just a swatch — here's how #577CEB works with other colors. Named schemes with #577CEB in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #577CEB Accent #A5C4C2 Surface #EAD5C0 Secondary #9AA0A1 Anchor #21344A

Signal 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 #577CEB Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #7EA4FF

Signal 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 Signal Blue.

Vintage Leather Lead · 5 colors

Lead #577CEB Secondary #7F4535 Surface #EED7C2 Accent #365246 Anchor #58223A

Signal 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 #577CEB Surface #F6E5D8 Anchor #5B2143 Accent #E5C2CA Secondary #322B2F

Signal 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 #577CEB Secondary #9FAFD7 Support #9D8F88 Ink #18140F

Signal 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 Signal Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #577CEB 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 10/100

Cool

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

Softness 42/100

Moderate

Middle-weight — neither delicate nor heavy.

Depth 40/100

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 32/100

Low

A faint retro warmth without tipping into sepia.

Luxury 43/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 47/100

Moderate

Recognisable but shares space with nearby hues.

UI accent fit 85/100

Very high

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

Surface fit 18/100

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 #577CEB

For UI

For branding

For interior

For fashion

People also use #577CEB with

Baby Blue Medium Slate Blue Saffron Gainsboro Charcoal

UI roles & guardrails

Primary action Safe as a filled button with near-black label. AA

Body text Do not use for body copy on light surfaces. Avoid

Large display Fine for headings 24px+ on white. Pass

Background Pair with #141310 text at 4.9:1. Use

Subtle surface Use #E1E7F7 for cards and hover fills. Tint 80

Avoid beside #6356EB — 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 #577CEB 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: #577CEB;
  --color-base-rgb: 87 124 235;
  --color-base-oklch: oklch(61.5% 0.172 267.3);
  --color-50: #F1F4FE;
  --color-100: #DAE2FC;
  --color-200: #B6C6F6;
  --color-300: #859EEB;
  --color-400: #5878DA;
  --color-500: #3558C0;
  --color-600: #304892;
  --color-700: #283767;
  --color-800: #1D2743;
  --color-900: #141929;
  --color-on-base: #141310;
}

// tailwind.config.js
colors: {
  signal-blue: {
    50: '#F1F4FE',
    100: '#DAE2FC',
    200: '#B6C6F6',
    300: '#859EEB',
    400: '#5878DA',
    500: '#3558C0',
    600: '#304892',
    700: '#283767',
    800: '#1D2743',
    900: '#141929',
  },
}

$base: #577CEB;
$base-ink: #141310;
$base-50: #F1F4FE;
$base-100: #DAE2FC;
$base-200: #B6C6F6;
$base-300: #859EEB;
$base-400: #5878DA;
$base-500: #3558C0;
$base-600: #304892;
$base-700: #283767;
$base-800: #1D2743;
$base-900: #141929;
$base-hover: #1D4FE4;
$base-subtle: #D2DAF4;

{
    "color": {
        "base": {
            "value": "#577CEB",
            "type": "color"
        },
        "onBase": {
            "value": "#141310",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F1F4FE",
                "type": "color"
            },
            "100": {
                "value": "#DAE2FC",
                "type": "color"
            },
            "200": {
                "value": "#B6C6F6",
                "type": "color"
            },
            "300": {
                "value": "#859EEB",
                "type": "color"
            },
            "400": {
                "value": "#5878DA",
                "type": "color"
            },
            "500": {
                "value": "#3558C0",
                "type": "color"
            },
            "600": {
                "value": "#304892",
                "type": "color"
            },
            "700": {
                "value": "#283767",
                "type": "color"
            },
            "800": {
                "value": "#1D2743",
                "type": "color"
            },
            "900": {
                "value": "#141929",
                "type": "color"
            }
        }
    }
}

Palettes built on #577CEB

Color Lab

Pairs with #577CEB

UI roles & guardrails

In real applications

Scales

Every model

Export