Tailwind CSS v3 color

Tailwind indigo-500 #6366F1

Tailwind CSS v3's indigo-500 is #6366F1. It is a vivid blue in the blue family. In OKLCH it sits at lightness 0.585, chroma 0.204 and hue 277.1°. The nearest CSS named color is mediumslateblue (#7B68EE), ΔE2000 3.9 away.

Relative luminance
0.1851
OKLCH L · C · h
0.585 · 0.204 · 277.1
Best text
Black 4.70:1
Hue family
Blue
Inspect this color Check contrast

#6366F1 color codes

HEX
#6366F1
RGB
rgb(99, 102, 241)
HSL
hsl(239, 84%, 67%)
OKLCH
oklch(0.585 0.204 277.1)
OKLab
oklab(0.585 0.025 -0.202)
CIELAB (D65)
L* 50.10, a* 38.69, b* -70.49
XYZ (D65)
X 25.77, Y 18.50, Z 85.42
CMYK (naive)
cmyk(59%, 58%, 0%, 5%)

CIELAB and XYZ use the D65 white point; CSS lab() uses D50, so paste the OKLCH or HEX value into stylesheets. CMYK here is a plain formula with no press profile.

Legibility

Contrast: is #6366F1 accessible?

Black text on it reaches 4.70:1, passing AA. White text manages only 4.46:1, enough for large text only.

WCAG 2 gives the same ratio whichever color is the text; APCA does not, so its Lc changes sign and size with polarity.

Open the Contrast System

  • Black text on it

    4.70:1

    • AA passes
    • AA large passes
    • AAA fails
    • APCA Lc +33

  • White text on it

    4.46:1

    • AA fails
    • AA large passes
    • AAA fails
    • APCA Lc −76

  • As text on black

    4.70:1

    • AA passes
    • AA large passes
    • AAA fails
    • APCA Lc −31

  • As text on white

    4.46:1

    • AA fails
    • AA large passes
    • AAA fails
    • APCA Lc +70

Nearest versions that pass 4.5:1

  • For text on white

    #6264EF 4.57:1

    Darkening its OKLCH lightness from 0.59 to 0.58 reaches 4.57:1 on white, keeping the hue.

    Compare both in the Contrast System

  • For text on black

    #6366F1 4.70:1

    It already reaches 4.70:1 on black, so no change is needed.

Checking another pair? Use the Contrast Checker.

Studio

Adjust #6366F1 live

Move lightness, chroma and hue in OKLCH, or drag on the map. The map is every lightness and chroma at the current hue: sRGB inside the solid area, Display P3 out to the dashed line.

The studio needs JavaScript.

Scale

Shades and tints of #6366F1

Eleven OKLCH lightness steps at this hue, each with its contrast against white and black. #6366F1 sits at step 500.

  1. 50#F2F4FF
    White
    1.09
    Black
    19.15
  2. 100#E6EAFF
    White
    1.19
    Black
    17.57
  3. 200#CDD5FF
    White
    1.44
    Black
    14.55
  4. 300#ADB8FF
    White
    1.89
    Black
    11.07
  5. 400#8B96FF
    White
    2.65
    Black
    7.90
  6. 500This color#6366F1
    White
    4.46
    Black
    4.70
  7. 600#5758E1
    White
    5.40
    Black
    3.88
  8. 700#443FC2
    White
    7.67
    Black
    2.73
  9. 800#31229F
    White
    11.29
    Black
    1.86
  10. 900#1F017A
    White
    15.62
    Black
    1.34
  11. 950#10004C
    White
    18.64
    Black
    1.12

Under each step, white and black text on it; a bold figure passes 4.5:1.

Tailwind CSS v3 indigo scale

The real Tailwind palette, for comparison with the computed ramp above.

  1. 50#EEF2FF
    White
    1.11
    Black
    18.78
  2. 100#E0E7FF
    White
    1.23
    Black
    17.04
  3. 200#C7D2FE
    White
    1.49
    Black
    14.07
  4. 300#A5B4FC
    White
    1.99
    Black
    10.53
  5. 400#818CF8
    White
    2.98
    Black
    7.04
  6. 500This color#6366F1
    White
    4.46
    Black
    4.70
  7. 600#4F46E5
    White
    6.28
    Black
    3.33
  8. 700#4338CA
    White
    7.90
    Black
    2.65
  9. 800#3730A3
    White
    9.93
    Black
    2.11
  10. 900#312E81
    White
    11.42
    Black
    1.83
  11. 950#1E1B4B
    White
    15.98
    Black
    1.31

Gamut

How vivid #6366F1 can get

At its lightness and hue, sRGB reaches OKLCH chroma 0.229; #6366F1 uses 89% of it. Display P3, which many recent phones and laptops show, reaches 0.247 there: 8% more.

0.00.20.40.60.80.20.40.60.8 460480500520540560580600620
  • sRGB
  • Display P3
  • Rec. 2020
  • Dominant wavelength
OKLCH chroma
0.204
sRGB edge
0.229
Display P3 edge
0.247
Rec. 2020 edge
0.250
Dominant wavelength
465 nm
Excitation purity
64%
Chromaticity
x 0.1987, y 0.1427
  • This color#6366F1
  • Most vivid in sRGB#6260FF
  • Most vivid in Display P3oklch(0.585 0.247 277.1)

On a screen without Display P3 the last tile shows the sRGB edge instead.

Use the wider color where screens show it
.accent {
  color: #6366f1;
}
@media (color-gamut: p3) {
  .accent { color: color(display-p3 0.3769 0.3581 1); }
}

Mixing

Mixing #6366F1

Each row is the same mix worked out in a different space, with the halfway color at its end. sRGB, which older CSS gradients use, can sag gray or dark in the middle; OKLab keeps the lightness steps even; OKLCH holds chroma and hue as it goes.

White #FFFFFF

  • sRGB50%#B1B3F8
  • OKLab50%#ABB6FD
  • OKLCH50%#ABB6FD

Black #000000

  • sRGB50%#323379
  • OKLab50%#21235D
  • OKLCH50%#21235D

Its complement #907B00

  • sRGB50%#7A7179
  • OKLab50%#757A95
  • OKLCH50%#008F86
In CSS
/* A gradient and a mix, worked out in OKLCH */
background: linear-gradient(in oklch, #6366f1, white);
color: color-mix(in oklch, #6366f1 50%, white);

In use

#6366F1 in an interface

A button, a link, a heading, a focused field, an icon and a chart line in this color, on a light page and a dark one. Each check is a WCAG 2 contrast minimum: 1.4.3 for text, 1.4.11 for the rest.

Light page

  • Button labelText, 4.5:14.70:1 Passes
  • Link and body-size textText, 4.5:14.46:1 Fails
  • Large headingLarge text, 3:14.46:1 Passes
  • Icons, borders and focus ringsNon-text, 3:14.46:1 Passes

For text on this page, the nearest shade that passes is #6264EF 4.57:1

Dark page

  • Button labelText, 4.5:14.70:1 Passes
  • Link and body-size textText, 4.5:14.19:1 Fails
  • Large headingLarge text, 3:14.19:1 Passes
  • Icons, borders and focus ringsNon-text, 3:14.19:1 Passes

For text on this page, the nearest shade that passes is #686CF8 4.53:1

Color vision

How #6366F1 looks with color blindness

Achromatopsia changes it most, ΔE2000 28.6; deuteranopia changes it least, 10.0.

Simulated with Machado et al. (2009) at full severity, in linear light.

Simulate a whole page What each type sees

  • Protanopia

    No working red (long-wavelength) cones

    #007DF6 ΔE2000 12.7

    Distinct

    Reads as vivid blue

  • Deuteranopia

    No working green (medium-wavelength) cones

    #0071EE ΔE2000 10.0

    Distinct

    Reads as vivid blue

  • Tritanopia

    No working blue (short-wavelength) cones

    #0087A2 ΔE2000 23.9

    Distinct

    Reads as soft blue

  • Achromatopsia

    No cone color vision; lightness only

    #777777 ΔE2000 28.6

    Distinct

    Reads as gray

Pairing check

Checked against its complement, #907B00. Their lightness contrast is only 1.06:1, so where hue collapses, add a label, icon or pattern.

VisionThe pairΔE2000Verdict
Normal vision#6366F1 · #907B0064.3Stays distinct
Protanopia#007DF6 · #89780060.0Stays distinct
Deuteranopia#0071EE · #8F7F1061.2Stays distinct
Tritanopia#0087A2 · #9D706843.5Stays distinct
Achromatopsia#777777 · #7C7C7C2.0Easily confused

Harmony

Color harmonies for #6366F1

Its complement is #907B00, a soft amber, on the warm side of the wheel.

Hue rotations in OKLCH, mapped into sRGB by trimming chroma so hue and lightness stay put.

Open the Harmony Studio
  • Base#6366F1
  • Complement#907B00

Complementary

Open in Harmony Studio
  • −30°#0080D1
  • Base#6366F1
  • +30°#9C4FD8

Analogous

Open in Harmony Studio
  • Base#6366F1
  • +120°#D64000
  • +240°#009459

Triadic

Open in Harmony Studio
  • Base#6366F1
  • +150°#AE6A00
  • +210°#638B00

Split-complementary

Open in Harmony Studio

Code

Design tokens

Ready-to-paste tokens in six formats. Rename them to fit your system.

CSS custom property

:root {
  --color-indigo-500: #6366f1;
}

Tailwind config

// tailwind.config.js — already built in as indigo-500;
// pin the v3 value explicitly like this:
module.exports = {
  theme: {
    extend: {
      colors: {
        indigo: { 500: '#6366f1' },
      },
    },
  },
};

Tailwind v4 theme

/* app.css — Tailwind CSS v4 */
@import "tailwindcss";

@theme {
  /* v4 has its own indigo-500; this pins the v3 value. */
  --color-indigo-500: oklch(0.585 0.204 277.1);
}

Design token (W3C DTCG)

{
  "color": {
    "indigo-500": {
      "$type": "color",
      "$value": {
        "colorSpace": "srgb",
        "components": [0.3882, 0.4, 0.9451],
        "hex": "#6366f1"
      },
      "$description": "Tailwind CSS v3 indigo-500"
    }
  }
}

SwiftUI color

import SwiftUI

enum Palette {
    static let indigo500 = Color(.sRGB, red: 0.388, green: 0.400, blue: 0.945, opacity: 1)
}

Jetpack Compose color

import androidx.compose.ui.graphics.Color

object Palette {
    val Indigo500 = Color(0xFF6366F1)
}

Matches

The nearest match in each system

The closest CSS name, Tailwind shade, RAL Classic paint and Crayola crayon by ΔE2000; under 2 is hard to tell apart side by side. RAL and Crayola values approximate physical colors.

Neighbors

The eight nearest colors on this site by ΔE2000, closest first. Under 2 is hard to tell apart side by side.

Tools

Open #6366F1 in the tools

Each opens over this page. More colors live in the Color Library, and every color page is listed on the hub.