Is #3F404C accessible for body text on white?

#3F404C has a contrast ratio of 10.25:1 against white, which is sufficient for WCAG AA body text (4.5:1).

What is the complementary color of #3F404C?

The complement of #3F404C is #4C4B3F.

#3F404C Charcoal

rgb(63, 64, 76)

Color conversions

HEX: #3F404C
RGB: rgb(63, 64, 76)
RGBA: rgba(63, 64, 76, 1)
HSL: hsl(235, 9%, 27%)
HSV / HSB: hsv(235, 17%, 30%)
CMYK: cmyk(17%, 16%, 0%, 70%)

Wide-gamut spaces

XYZ: xyz(5.188, 5.245, 7.575)
LAB: lab(27.42 2.49 -7.39)
LCH: lch(27.42 7.8 288.65)
OKLAB: oklab(37.52% 0.0041 -0.02)
OKLCH: oklch(37.52% 0.0205 281.6)
Nearest name: Charcoal

Shades, tints and tones

Shades

Tints

Tones

Color harmonies

Complementary

The hue directly opposite on the color wheel. Maximum contrast, ideal for a single accent against a dominant brand color.

Analogous

Neighbouring hues that share a temperature. The safest harmony for calm, cohesive interfaces.

Triadic

Three hues evenly spaced 120 degrees apart. Vibrant and balanced — use one as dominant and the other two sparingly.

Split Complementary

The complement split into two adjacent hues. Nearly the contrast of complementary with noticeably less tension.

Square (Tetradic)

Four hues at 90-degree intervals. A rich set for illustration, data visualisation, and category coding.

Rectangle (Tetradic)

Two complementary pairs offset by 60 degrees. Gives two warm and two cool options in one system.

Monochromatic

A single hue across five lightness levels. The foundation of most UI scales and the most accessible starting point.

Similar colors

Closest matches

Opacity variations

#3f404c1a

#3f404c33

#3f404c4d

#3f404c66

#3f404c80

#3f404c99

#3f404cb3

#3f404ccc

#3f404ce6

#3f404cff

On white

10.25:1

Body text AAA · Large text AA

On black

2.05:1

Body text Fail · Large text Fail

White-on-color contrast is 10.25:1.

Color blindness preview

Protanopia

No red cones — ~1% of men

Protanomaly

Reduced red sensitivity — ~1% of men

Deuteranopia

No green cones — ~1% of men

Deuteranomaly

Reduced green sensitivity — ~5% of men

Tritanopia

No blue cones — very rare

Tritanomaly

Reduced blue sensitivity — very rare

Achromatopsia

No color perception — ~1 in 30,000

Achromatomaly

Partial color perception — rare

Meaning, psychology and brand usage

The structural colour every interface actually runs on

Neutral grays carry no emotional charge, which is precisely their value: they let content and brand colour do the signalling. Their temperature matters more than designers expect — a cool gray beside a warm brand colour reads as a mistake.

Neutrality, professionalism, and precision. Overuse reads as noncommittal or unfinished.

Payne's gray, mixed rather than mined, became the painter's shortcut for atmospheric shadow. Swiss modernism turned systematic gray scales into a design methodology.

Build a full gray ramp before choosing a brand colour. Match the gray's temperature to the brand hue and reserve the darkest steps for type rather than large fills.

Common industries: Enterprise, Architecture, Automotive, Consulting, Hardware. Pairs well with a single saturated accent, warm white for text surfaces, near-black for hierarchy.

Code exports

CSS

:root {
  --color-charcoal: #3f404c;
  --color-charcoal-rgb: 63 64 76;
  --color-charcoal-hsl: 235 9% 27%;
  --color-charcoal-oklch: 37.52% 0.0205 281.6;
}

.element {
  color: #3f404c;
  background-color: hsl(235, 9%, 27%);
  border: 1px solid rgb(63 64 76 / 40%);
}

SCSS

$charcoal: #3f404c;
$charcoal-light: #9fa0a6;
$charcoal-dark: #202026;

.element {
  color: $charcoal;
  background: rgba($charcoal, 0.12);

  &:hover {
    color: darken($charcoal, 8%);
  }
}

LESS

@charcoal: #3f404c;
@charcoal-light: lighten(@charcoal, 12%);
@charcoal-dark: darken(@charcoal, 12%);

.element {
  color: @charcoal;
  background: fade(@charcoal, 12%);
}

Tailwind CSS

/* Tailwind v4 — src/styles.css */
@theme {
  --color-charcoal-50: #d9d9db;
  --color-charcoal-100: #c5c6c9;
  --color-charcoal-200: #b2b3b7;
  --color-charcoal-300: #8c8c94;
  --color-charcoal-400: #656670;
  --color-charcoal-500: #3f404c;
  --color-charcoal-600: #393a44;
  --color-charcoal-700: #2c2d35;
  --color-charcoal-800: #202026;
  --color-charcoal-900: #131317;
}

/* Usage */
<div class="bg-charcoal-500 text-charcoal-50 ring-charcoal-600" />

/* Arbitrary value, no config needed */
<div class="bg-[#3f404c]" />

Bootstrap

// Bootstrap 5 — _variables.scss (before importing bootstrap)
$charcoal: #3f404c;
$primary: $charcoal;

$theme-colors: map-merge($theme-colors, (
  "charcoal": $charcoal
));

// Generates .text-charcoal, .bg-charcoal, .btn-charcoal
@import "bootstrap/scss/bootstrap";

Flutter

import 'package:flutter/material.dart';

const Color charcoal = Color(0xFF3F404C);

// As a MaterialColor swatch
const MaterialColor charcoalSwatch = MaterialColor(0xFF3F404C, <int, Color>{
  50: Color(0xFFD9D9DB),
  100: Color(0xFFC5C6C9),
  200: Color(0xFFB2B3B7),
  300: Color(0xFF8C8C94),
  400: Color(0xFF656670),
  500: Color(0xFF3F404C),
  600: Color(0xFF393A44),
  700: Color(0xFF2C2D35),
  800: Color(0xFF202026),
  900: Color(0xFF131317),
});

Swift / SwiftUI

import SwiftUI

extension Color {
    /// #3f404c — Charcoal
    static let charcoal = Color(
        red: 0.2471,
        green: 0.251,
        blue: 0.298
    )
}

// UIKit
extension UIColor {
    static let charcoal = UIColor(
        red: 0.2471,
        green: 0.251,
        blue: 0.298,
        alpha: 1.0
    )
}

Android

<!-- res/values/colors.xml -->
<resources>
    <color name="charcoal">#3F404C</color>
    <color name="charcoal_translucent">#803F404C</color>
</resources>

<!-- Jetpack Compose -->
val Charcoal = Color(0xFF3F404C)

JavaScript

export const CHARCOAL = {
  hex: "#3f404c",
  rgb: [63, 64, 76],
  hsl: [235, 9, 27],
  oklch: "oklch(37.52% 0.0205 281.6)",
};

JSON tokens

{
  "$schema": "https://design-tokens.org/schema.json",
  "charcoal": {
    "$type": "color",
    "$value": "#3f404c",
    "$description": "Charcoal — generated by ColorVerse AI"
  }
}