What color is #3F64BB?

#3F64BB is a medium blue. In RGB it is rgb(63, 100, 187), and in HSL hsl(222, 50%, 49%).

Is #3F64BB accessible as text?

On white, #3F64BB has a contrast ratio of 5.60:1 (passes WCAG AA for body text); on black it is 3.75:1 (fails). For text placed on #3F64BB, use white for the best readability.

What is the closest Tailwind color to #3F64BB?

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

What colors go well with #3F64BB?

#3F64BB pairs cleanly with neutrals — cream, taupe, charcoal and cool grays — and with its complementary #BB963E. In UI, a softer accent is often easier to use than the exact complement. Explore the harmonies, shades, tints and ready-made palettes for #3F64BB below.

Is #3F64BB good for buttons?

#3F64BB works well for buttons and highlights, but use white text on #3F64BB — black text only reaches 3.75:1, below the 4.5:1 needed for normal-size labels.

Is #3F64BB the same as CSS royalblue?

No — #3F64BB is not the CSS named color royalblue, but royalblue (#4169E1) is the closest CSS named color.

#3F64BB Color — HEX, RGB, HSL, Palette & Shades

Palettes built on #3F64BB

Not just a swatch — here's how #3F64BB works with other colors. Named schemes with #3F64BB in its natural role, and a note on why the supporting colors balance it.

Coastal Morning Lead · 5 colors

Lead #3F64BB Accent #A5C4C2 Surface #DDDBBF Secondary #9AA0A1 Anchor #21344A

Denim 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 #3F64BB Surface #14161A Highlight #F4F6F8 Secondary #5A6672 Accent #658ADB

Denim 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 Denim Blue.

Vintage Leather Lead · 5 colors

Lead #3F64BB Secondary #7F4536 Surface #EED7C2 Accent #365246 Anchor #58223A

Denim 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 #3F64BB Surface #F6E5D8 Anchor #5B2144 Accent #E5C2CA Secondary #322B2F

Denim 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 #3F64BB Secondary #8393B2 Support #9D8F88 Ink #18140F

Denim 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 Denim Blue carrying the quiet middle.

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Color Lab

How #3F64BB 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 15/100

Cool

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

Softness 40/100

Low

Middle-weight — neither delicate nor heavy.

Depth 49/100

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 43/100

Moderate

A faint retro warmth without tipping into sepia.

Luxury 53/100

Moderate

Understated — leans refined without going austere.

Brand distinctiveness 39/100

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 11/100

Very low

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

Print safety 74/100

High

Reproduces faithfully in CMYK — safe for packaging and print.

Pairs with #3F64BB

For UI

For branding

For interior

For fashion

People also use #3F64BB with

Lagoon Blue Grape Dijon 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 5.6:1. Use

Subtle surface Use #DCE1EE for cards and hover fills. Tint 80

Avoid beside #433EBB — 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 #3F64BB at work across the surfaces designers actually ship.

Website / UI

Northwind Sign up

Build faster.

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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: #3F64BB;
  --color-base-rgb: 63 100 187;
  --color-base-oklch: oklch(52.2% 0.143 264.6);
  --color-50: #F3F6FC;
  --color-100: #E0E6F5;
  --color-200: #C2CEEB;
  --color-300: #97ABD8;
  --color-400: #7088C2;
  --color-500: #4E69A6;
  --color-600: #425480;
  --color-700: #333F5C;
  --color-800: #242C3C;
  --color-900: #181C25;
  --color-on-base: #FFFFFF;
}

// tailwind.config.js
colors: {
  denim-blue: {
    50: '#F3F6FC',
    100: '#E0E6F5',
    200: '#C2CEEB',
    300: '#97ABD8',
    400: '#7088C2',
    500: '#4E69A6',
    600: '#425480',
    700: '#333F5C',
    800: '#242C3C',
    900: '#181C25',
  },
}

$base: #3F64BB;
$base-ink: #FFFFFF;
$base-50: #F3F6FC;
$base-100: #E0E6F5;
$base-200: #C2CEEB;
$base-300: #97ABD8;
$base-400: #7088C2;
$base-500: #4E69A6;
$base-600: #425480;
$base-700: #333F5C;
$base-800: #242C3C;
$base-900: #181C25;
$base-hover: #325096;
$base-subtle: #C9D2E7;

{
    "color": {
        "base": {
            "value": "#3F64BB",
            "type": "color"
        },
        "onBase": {
            "value": "#FFFFFF",
            "type": "color"
        },
        "scale": {
            "50": {
                "value": "#F3F6FC",
                "type": "color"
            },
            "100": {
                "value": "#E0E6F5",
                "type": "color"
            },
            "200": {
                "value": "#C2CEEB",
                "type": "color"
            },
            "300": {
                "value": "#97ABD8",
                "type": "color"
            },
            "400": {
                "value": "#7088C2",
                "type": "color"
            },
            "500": {
                "value": "#4E69A6",
                "type": "color"
            },
            "600": {
                "value": "#425480",
                "type": "color"
            },
            "700": {
                "value": "#333F5C",
                "type": "color"
            },
            "800": {
                "value": "#242C3C",
                "type": "color"
            },
            "900": {
                "value": "#181C25",
                "type": "color"
            }
        }
    }
}

Palettes built on #3F64BB

Color Lab

Pairs with #3F64BB

UI roles & guardrails

In real applications

Scales

Every model

Export