What color is #3F5ABC?

#3F5ABC is a medium blue. In RGB it is rgb(63, 90, 188), and in HSL hsl(227, 50%, 49%).

Is #3F5ABC accessible as text?

On white, #3F5ABC has a contrast ratio of 6.18:1 (passes WCAG AA for body text); on black it is 3.40:1 (fails). For text placed on #3F5ABC, use white for the best readability.

What is the closest Tailwind color to #3F5ABC?

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

What colors go well with #3F5ABC?

#3F5ABC pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #BBA03E. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #3F5ABC below.

Is #3F5ABC good for buttons?

#3F5ABC works well for buttons and highlights, but use white text on #3F5ABC — black text only reaches 3.40:1, below the 4.5:1 needed for normal-size labels.

Is #3F5ABC the same as CSS slateblue?

No — #3F5ABC is not the CSS named color slateblue, but slateblue (#6A5ACD) is the closest CSS named color.

#3F5ABC Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #3F5ABC

Not just a swatch — here's how #3F5ABC works with other colors. Named schemes with #3F5ABC in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #3F5ABC Accent #A5C4C2 Surface #EAD5C0 Secondary #9AA0A1 Anchor #21344A

Cerulean 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 #3F5ABC Surface #14161A Highlight #F4F6F8 Secondary #5B6672 Accent #6380DB

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

Vintage Leather Lead · 5 colors

Lead #3F5ABC Secondary #7F4535 Surface #EED7C2 Accent #365246 Anchor #58223A

Cerulean 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 #3F5ABC Surface #F6E5D8 Anchor #5B2143 Accent #E5C2CA Secondary #322B2F

Cerulean 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 #3F5ABC Secondary #7E8CAF Support #9D8F88 Ink #18140F

Cerulean 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 Cerulean carrying the quiet middle.

Build a working theme in the generator →

Color Lab

How #3F5ABC 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 37/100

Low

Middle-weight — neither delicate nor heavy.

Depth 52/100

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 38/100

Low

A faint retro warmth without tipping into sepia.

Luxury 54/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 42/100

Moderate

Recognisable but shares space with nearby hues.

UI accent fit 98/100

Very high

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

Surface fit 8/100

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 #3F5ABC

For UI

For branding

For interior

For fashion

People also use #3F5ABC with

Iceberg Grape Brass Gainsboro Gunmetal Gray

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 6.2:1. Use

Subtle surface Use #DCE0EE for cards and hover fills. Tint 80

Avoid beside #4D3EBB — 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 #3F5ABC 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: #3F5ABC;
  --color-base-rgb: 63 90 188;
  --color-base-oklch: oklch(50.1% 0.157 268.6);
  --color-50: #F3F5FC;
  --color-100: #E0E4F5;
  --color-200: #C2CBEB;
  --color-300: #97A5D8;
  --color-400: #7082C2;
  --color-500: #4E61A6;
  --color-600: #424F80;
  --color-700: #333C5C;
  --color-800: #242A3C;
  --color-900: #181B25;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  cerulean: {
    50: '#F3F5FC',
    100: '#E0E4F5',
    200: '#C2CBEB',
    300: '#97A5D8',
    400: '#7082C2',
    500: '#4E61A6',
    600: '#424F80',
    700: '#333C5C',
    800: '#242A3C',
    900: '#181B25',
  },
}

$base: #3F5ABC;
$base-ink: #FFFFFF;
$base-50: #F3F5FC;
$base-100: #E0E4F5;
$base-200: #C2CBEB;
$base-300: #97A5D8;
$base-400: #7082C2;
$base-500: #4E61A6;
$base-600: #424F80;
$base-700: #333C5C;
$base-800: #242A3C;
$base-900: #181B25;
$base-hover: #324896;
$base-subtle: #C9D0E7;

{
    "color": {
        "base": {
            "value": "#3F5ABC",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F3F5FC",
                "type": "color"
            },
            "100": {
                "value": "#E0E4F5",
                "type": "color"
            },
            "200": {
                "value": "#C2CBEB",
                "type": "color"
            },
            "300": {
                "value": "#97A5D8",
                "type": "color"
            },
            "400": {
                "value": "#7082C2",
                "type": "color"
            },
            "500": {
                "value": "#4E61A6",
                "type": "color"
            },
            "600": {
                "value": "#424F80",
                "type": "color"
            },
            "700": {
                "value": "#333C5C",
                "type": "color"
            },
            "800": {
                "value": "#242A3C",
                "type": "color"
            },
            "900": {
                "value": "#181B25",
                "type": "color"
            }
        }
    }
}

Palettes built on #3F5ABC

Color Lab

Pairs with #3F5ABC

UI roles & guardrails

In real applications

Scales

Every model

Export