Is #6366FC accessible for body text on white?

#6366FC has a contrast ratio of 4.34:1 against white, which is not sufficient for WCAG AA body text (4.5:1).

What is the complementary color of #6366FC?

The complement of #6366FC is #FCF963.

#6366FC Medium Slate Blue

rgb(99, 102, 252)

Color conversions

HEX: #6366FC
RGB: rgb(99, 102, 252)
RGBA: rgba(99, 102, 252, 1)
HSL: hsl(239, 96%, 69%)
HSV / HSB: hsv(239, 61%, 99%)
CMYK: cmyk(61%, 60%, 0%, 1%)

Wide-gamut spaces

XYZ: xyz(27.462, 19.182, 94.332)
LAB: lab(50.9 42.19 -75.32)
LCH: lch(50.9 86.33 299.26)
OKLAB: oklab(59.38% 0.0251 -0.2167)
OKLCH: oklch(59.38% 0.2181 276.6)
Nearest name: Medium Slate Blue

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

#6366fc1a

#6366fc33

#6366fc4d

#6366fc66

#6366fc80

#6366fc99

#6366fcb3

#6366fccc

#6366fce6

#6366fcff

On white

4.34:1

Body text AA Large · Large text AA

On black

4.84:1

Body text AA · Large text AA

White-on-color contrast is 4.34:1.

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 default of trust — and of everything else

Blue lowers perceived risk and is consistently rated as the most trustworthy hue, which is exactly why it saturates finance, enterprise software, and social platforms. Its ubiquity is now its weakness: a blue primary is safe but rarely memorable.

Trust, stability, and competence in Western markets; immortality in parts of East Asia; and protection against the evil eye across the Mediterranean and Middle East.

Ultramarine was ground from lapis lazuli and once cost more than gold, which is why medieval painters reserved it for the Virgin's robes. Synthetic ultramarine in 1826 democratised it almost overnight.

Reliable as a primary in any category that must feel secure. Differentiate by pushing toward an unusual chroma or pairing with an unexpected accent rather than defaulting to blue-plus-gray.

Common industries: Finance, Enterprise software, Insurance, Government, Aviation. Pairs well with warm amber for energy, crisp white for clarity, rose for a contemporary contrast.

Code exports

CSS

:root {
  --color-medium-slate-blue: #6366fc;
  --color-medium-slate-blue-rgb: 99 102 252;
  --color-medium-slate-blue-hsl: 239 96% 69%;
  --color-medium-slate-blue-oklch: 59.38% 0.2181 276.6;
}

.element {
  color: #6366fc;
  background-color: hsl(239, 96%, 69%);
  border: 1px solid rgb(99 102 252 / 40%);
}

SCSS

$medium-slate-blue: #6366fc;
$medium-slate-blue-light: #b1b3fe;
$medium-slate-blue-dark: #32337e;

.element {
  color: $medium-slate-blue;
  background: rgba($medium-slate-blue, 0.12);

  &:hover {
    color: darken($medium-slate-blue, 8%);
  }
}

LESS

@medium-slate-blue: #6366fc;
@medium-slate-blue-light: lighten(@medium-slate-blue, 12%);
@medium-slate-blue-dark: darken(@medium-slate-blue, 12%);

.element {
  color: @medium-slate-blue;
  background: fade(@medium-slate-blue, 12%);
}

Tailwind CSS

/* Tailwind v4 — src/styles.css */
@theme {
  --color-medium-slate-blue-50: #e0e0fe;
  --color-medium-slate-blue-100: #d0d1fe;
  --color-medium-slate-blue-200: #c1c2fe;
  --color-medium-slate-blue-300: #a1a3fd;
  --color-medium-slate-blue-400: #8285fd;
  --color-medium-slate-blue-500: #6366fc;
  --color-medium-slate-blue-600: #595ce3;
  --color-medium-slate-blue-700: #4547b0;
  --color-medium-slate-blue-800: #32337e;
  --color-medium-slate-blue-900: #1e1f4c;
}

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

/* Arbitrary value, no config needed */
<div class="bg-[#6366fc]" />

Bootstrap

// Bootstrap 5 — _variables.scss (before importing bootstrap)
$medium-slate-blue: #6366fc;
$primary: $medium-slate-blue;

$theme-colors: map-merge($theme-colors, (
  "medium-slate-blue": $medium-slate-blue
));

// Generates .text-medium-slate-blue, .bg-medium-slate-blue, .btn-medium-slate-blue
@import "bootstrap/scss/bootstrap";

Flutter

import 'package:flutter/material.dart';

const Color mediumSlateBlue = Color(0xFF6366FC);

// As a MaterialColor swatch
const MaterialColor mediumSlateBlueSwatch = MaterialColor(0xFF6366FC, <int, Color>{
  50: Color(0xFFE0E0FE),
  100: Color(0xFFD0D1FE),
  200: Color(0xFFC1C2FE),
  300: Color(0xFFA1A3FD),
  400: Color(0xFF8285FD),
  500: Color(0xFF6366FC),
  600: Color(0xFF595CE3),
  700: Color(0xFF4547B0),
  800: Color(0xFF32337E),
  900: Color(0xFF1E1F4C),
});

Swift / SwiftUI

import SwiftUI

extension Color {
    /// #6366fc — Medium Slate Blue
    static let mediumSlateBlue = Color(
        red: 0.3882,
        green: 0.4,
        blue: 0.9882
    )
}

// UIKit
extension UIColor {
    static let mediumSlateBlue = UIColor(
        red: 0.3882,
        green: 0.4,
        blue: 0.9882,
        alpha: 1.0
    )
}

Android

<!-- res/values/colors.xml -->
<resources>
    <color name="medium_slate_blue">#6366FC</color>
    <color name="medium_slate_blue_translucent">#806366FC</color>
</resources>

<!-- Jetpack Compose -->
val MediumSlateBlue = Color(0xFF6366FC)

JavaScript

export const MEDIUM_SLATE_BLUE = {
  hex: "#6366fc",
  rgb: [99, 102, 252],
  hsl: [239, 96, 69],
  oklch: "oklch(59.38% 0.2181 276.6)",
};

JSON tokens

{
  "$schema": "https://design-tokens.org/schema.json",
  "medium-slate-blue": {
    "$type": "color",
    "$value": "#6366fc",
    "$description": "Medium Slate Blue — generated by ColorVerse AI"
  }
}