CSS named color

Turquoise #40E0D0

The CSS keyword turquoise is #40E0D0. It is a pale soft cyan in the cyan family. In OKLCH it sits at lightness 0.822, chroma 0.131 and hue 185.1°.

Relative luminance
0.5896
OKLCH L · C · h
0.822 · 0.131 · 185.1
Best text
Black 12.79:1
Hue family
Cyan

#40E0D0 color codes

HEX
#40E0D0
RGB
rgb(64, 224, 208)
HSL
hsl(174, 72%, 56%)
OKLCH
oklch(0.822 0.131 185.1)
OKLab
oklab(0.822 -0.130 -0.012)
CIELAB (D65)
L* 81.26, a* -44.08, b* -4.03
XYZ (D65)
X 40.15, Y 58.95, Z 68.92
CMYK (naive)
cmyk(71%, 0%, 7%, 12%)

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 #40E0D0 accessible?

Black text on it reaches 12.79:1, passing AAA. White text fails at 1.64:1.

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

    12.79:1

    • AA passes
    • AA large passes
    • AAA passes
    • APCA Lc +75
  • White text on it

    1.64:1

    • AA fails
    • AA large fails
    • AAA fails
    • APCA Lc −31
  • As text on black

    12.79:1

    • AA passes
    • AA large passes
    • AAA passes
    • APCA Lc −74
  • As text on white

    1.64:1

    • AA fails
    • AA large fails
    • AAA fails
    • APCA Lc +28

Nearest versions that pass 4.5:1

  • For text on white

    #00847A 4.58:1

    Darkening its OKLCH lightness from 0.82 to 0.55 reaches 4.58:1 on white, keeping the hue.

  • For text on black

    #40E0D0 12.79:1

    It already reaches 12.79:1 on black, so no change is needed.

Checking another pair? Use the Contrast Checker.

Studio

Adjust #40E0D0 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 #40E0D0

Eleven OKLCH lightness steps at this hue, each with its contrast against white and black. #40E0D0 sits at step 300.

  1. 50#D7FFF9
    White
    1.07
    Black
    19.56
  2. 100#A5FFF3
    White
    1.15
    Black
    18.19
  3. 200#72F0E1
    White
    1.37
    Black
    15.26
  4. 300This color#40E0D0
    White
    1.64
    Black
    12.79
  5. 400#00BAAC
    White
    2.43
    Black
    8.61
  6. 500#009B8F
    White
    3.45
    Black
    6.08
  7. 600#008076
    White
    4.82
    Black
    4.34
  8. 700#00665E
    White
    6.85
    Black
    3.06
  9. 800#004B44
    White
    10.04
    Black
    2.08
  10. 900#00312C
    White
    14.23
    Black
    1.47
  11. 950#001B18
    White
    17.94
    Black
    1.16

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

Gamut

How vivid #40E0D0 can get

At its lightness and hue, sRGB reaches OKLCH chroma 0.145; #40E0D0 uses 90% of it. Display P3, which many recent phones and laptops show, reaches 0.196 there: 35% more.

0.00.20.40.60.80.20.40.60.8 460480500520540560580600620
  • sRGB
  • Display P3
  • Rec. 2020
  • Dominant wavelength
OKLCH chroma
0.131
sRGB edge
0.145
Display P3 edge
0.196
Rec. 2020 edge
0.314
Dominant wavelength
495 nm
Excitation purity
25%
Chromaticity
x 0.2390, y 0.3508
  • This color#40E0D0
  • Most vivid in sRGB#00E3D1
  • Most vivid in Display P3oklch(0.822 0.196 185.1)

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

Use the wider color where screens show it
.accent {
  color: #40e0d0;
}
@media (color-gamut: p3) {
  .accent { color: color(display-p3 0 0.9063 0.8362); }
}

Mixing

Mixing #40E0D0

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%#A0F0E8
  • OKLab50%#B1F0E7
  • OKLCH50%#B1F0E7

Black #000000

  • sRGB50%#207068
  • OKLab50%#13564F
  • OKLCH50%#13564F

Its complement #FFA8BC

  • sRGB50%#A0C4C6
  • OKLab50%#BCC8C6
  • OKLCH50%#B3C1FF
In CSS
/* A gradient and a mix, worked out in OKLCH */
background: linear-gradient(in oklch, #40e0d0, white);
color: color-mix(in oklch, #40e0d0 50%, white);

In use

#40E0D0 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, 4.5:112.79:1 Passes
  • Link and body-size textText, 4.5:11.64:1 Fails
  • Large headingLarge text, 3:11.64:1 Fails
  • Icons, borders and focus ringsNon-text, 3:11.64:1 Fails

For text on this page, the nearest shade that passes is #00847A 4.58:1

Dark page

  • Button labelText, 4.5:112.79:1 Passes
  • Link and body-size textText, 4.5:111.41:1 Passes
  • Large headingLarge text, 3:111.41:1 Passes
  • Icons, borders and focus ringsNon-text, 3:111.41:1 Passes

Color vision

How #40E0D0 looks with color blindness

Deuteranopia changes it most, ΔE2000 25.8; tritanopia changes it least, 2.7.

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

    #D5D3D0 ΔE2000 25.0

    Distinct

    Reads as light gray

  • Deuteranopia

    No working green (medium-wavelength) cones

    #BEC3D2 ΔE2000 25.8

    Distinct

    Reads as light grayish blue

  • Tritanopia

    No working blue (short-wavelength) cones

    #00E5DB ΔE2000 2.7

    Close match

    Reads as pale soft cyan

  • Achromatopsia

    No cone color vision; lightness only

    #CACACA ΔE2000 24.4

    Distinct

    Reads as light gray

Pairing check

Checked against its complement, #FFA8BC. Their lightness contrast is only 1.10:1, so where hue collapses, add a label, icon or pattern.

VisionThe pairΔE2000Verdict
Normal vision#40E0D0 · #FFA8BC62.0Stays distinct
Protanopia#D5D3D0 · #B5B7BD8.5Harder to tell apart
Deuteranopia#BEC3D2 · #CAC6BA13.2Stays distinct
Tritanopia#00E5DB · #FFA2AF57.8Stays distinct
Achromatopsia#CACACA · #C0C0C02.5Easily confused

Harmony

Color harmonies for #40E0D0

Its complement is #FFA8BC, a pale soft pink, 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#40E0D0
  • Complement#FFA8BC

Complementary

Open in Harmony Studio
  • −30°#79DE9F
  • Base#40E0D0
  • +30°#40DAFA
  • Base#40E0D0
  • +120°#D6B2FF
  • +240°#FFB263
  • Base#40E0D0
  • +150°#F9A4E6
  • +210°#FFAD98

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-turquoise: #40e0d0;
}

Tailwind config

// tailwind.config.js
module.exports = {
  theme: {
    extend: {
      colors: {
        turquoise: '#40e0d0',
      },
    },
  },
};

Tailwind v4 theme

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

@theme {
  --color-turquoise: oklch(0.822 0.131 185.1);
}

Design token (W3C DTCG)

{
  "color": {
    "turquoise": {
      "$type": "color",
      "$value": {
        "colorSpace": "srgb",
        "components": [0.251, 0.8784, 0.8157],
        "hex": "#40e0d0"
      },
      "$description": "CSS named color turquoise"
    }
  }
}

SwiftUI color

import SwiftUI

enum Palette {
    static let turquoise = Color(.sRGB, red: 0.251, green: 0.878, blue: 0.816, opacity: 1)
}

Jetpack Compose color

import androidx.compose.ui.graphics.Color

object Palette {
    val Turquoise = Color(0xFF40E0D0)
}

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.

Tools

Open #40E0D0 in the tools

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