What color is #366CBB?

#366CBB is a medium blue. In RGB it is rgb(54, 108, 187), and in HSL hsl(216, 55%, 47%).

Is #366CBB accessible as text?

On white, #366CBB has a contrast ratio of 5.22:1 (passes WCAG AA for body text); on black it is 4.02:1 (fails). For text placed on #366CBB, use white for the best readability.

What is the closest Tailwind color to #366CBB?

The nearest Tailwind CSS token is sky-700 (#0069A8).

What colors go well with #366CBB?

#366CBB pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #BA8536. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #366CBB below.

Is #366CBB good for buttons?

#366CBB works well for buttons and highlights, but use white text on #366CBB — black text only reaches 4.02:1, below the 4.5:1 needed for normal-size labels.

Is #366CBB the same as CSS royalblue?

No — #366CBB is not the CSS named color royalblue, but royalblue (#4169E1) is the closest CSS named color.

#366CBB Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #366CBB

Not just a swatch — here's how #366CBB works with other colors. Named schemes with #366CBB in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #366CBB Accent #A5C4C1 Surface #DDDBBF Secondary #9AA0A1 Anchor #20344A

True 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 #366CBB Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #6091DB

True 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 True Blue.

Vintage Leather Lead · 5 colors

Lead #366CBB Secondary #7F4537 Surface #E1DDC1 Accent #375246 Anchor #57223B

True 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 #366CBB Surface #EDE9D6 Anchor #5A2144 Accent #E4C2CA Secondary #322B2F

True Blue sits between cream and a deep berry here, softened by a blush accent and grounded by charcoal.

Minimal Editorial Surface · 5 colors

Surface #F6F4EF Accent #366CBB Secondary #8598B5 Support #9D8F89 Ink #16140F

True 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 True Blue carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #366CBB 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 14/100

Cool

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

Softness 41/100

Moderate

Middle-weight — neither delicate nor heavy.

Depth 48/100

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 45/100

Moderate

A faint retro warmth without tipping into sepia.

Luxury 52/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 37/100

Low

Recognisable but shares space with nearby hues.

UI accent fit 100/100

Very high

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

Surface fit 14/100

Very low

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

Print safety 73/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #366CBB

For UI

For branding

For interior

For fashion

People also use #366CBB with

Robin Egg Blue Cerulean Dark Goldenrod Gainsboro Charcoal

UI roles & guardrails

Primary action Safe as a filled button with white label. AA

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 5.2:1. Use

Subtle surface Use #D9E2EF for cards and hover fills. Tint 80

Avoid beside #363FBA — 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 #366CBB 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: #366CBB;
  --color-base-rgb: 54 108 187;
  --color-base-oklch: oklch(53.5% 0.137 258.0);
  --color-50: #F3F6FC;
  --color-100: #DFE8F6;
  --color-200: #C0D2ED;
  --color-300: #94B1DB;
  --color-400: #6B90C7;
  --color-500: #4A71AB;
  --color-600: #3F5A83;
  --color-700: #31435E;
  --color-800: #232E3E;
  --color-900: #171D26;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  true-blue: {
    50: '#F3F6FC',
    100: '#DFE8F6',
    200: '#C0D2ED',
    300: '#94B1DB',
    400: '#6B90C7',
    500: '#4A71AB',
    600: '#3F5A83',
    700: '#31435E',
    800: '#232E3E',
    900: '#171D26',
  },
}

$base: #366CBB;
$base-ink: #FFFFFF;
$base-50: #F3F6FC;
$base-100: #DFE8F6;
$base-200: #C0D2ED;
$base-300: #94B1DB;
$base-400: #6B90C7;
$base-500: #4A71AB;
$base-600: #3F5A83;
$base-700: #31435E;
$base-800: #232E3E;
$base-900: #171D26;
$base-hover: #2B5595;
$base-subtle: #C6D3E7;

{
    "color": {
        "base": {
            "value": "#366CBB",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F3F6FC",
                "type": "color"
            },
            "100": {
                "value": "#DFE8F6",
                "type": "color"
            },
            "200": {
                "value": "#C0D2ED",
                "type": "color"
            },
            "300": {
                "value": "#94B1DB",
                "type": "color"
            },
            "400": {
                "value": "#6B90C7",
                "type": "color"
            },
            "500": {
                "value": "#4A71AB",
                "type": "color"
            },
            "600": {
                "value": "#3F5A83",
                "type": "color"
            },
            "700": {
                "value": "#31435E",
                "type": "color"
            },
            "800": {
                "value": "#232E3E",
                "type": "color"
            },
            "900": {
                "value": "#171D26",
                "type": "color"
            }
        }
    }
}

Palettes built on #366CBB

Color Lab

Pairs with #366CBB

UI roles & guardrails

In real applications

Scales

Every model

Export