Tailwind CSS v3 color

Tailwind cyan-800 #155E75

Tailwind CSS v3's cyan-800 is #155E75. It is a dark muted blue in the cyan family. In OKLCH it sits at lightness 0.450, chroma 0.077 and hue 224.3°. The nearest CSS named color is darkslategray (#2F4F4F), ΔE2000 11.0 away.

Relative luminance
0.0945
OKLCH L · C · h
0.450 · 0.077 · 224.3
Best text
White 7.26:1
Hue family
Cyan
Inspect this color Check contrast

#155E75 color codes

HEX
#155E75
RGB
rgb(21, 94, 117)
HSL
hsl(194, 70%, 27%)
OKLCH
oklch(0.450 0.077 224.3)
OKLab
oklab(0.450 -0.055 -0.054)
CIELAB (D65)
L* 36.83, a* -13.07, b* -19.19
XYZ (D65)
X 7.52, Y 9.45, Z 18.25
CMYK (naive)
cmyk(82%, 20%, 0%, 54%)

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 #155E75 accessible?

White text on it reaches 7.26:1, passing AAA. Black text fails at 2.88:1.

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

    2.88:1

    • AA fails
    • AA large fails
    • AAA fails
    • APCA Lc +19

  • White text on it

    7.26:1

    • AA passes
    • AA large passes
    • AAA passes
    • APCA Lc −89

  • As text on black

    2.88:1

    • AA fails
    • AA large fails
    • AAA fails
    • APCA Lc −17

  • As text on white

    7.26:1

    • AA passes
    • AA large passes
    • AAA passes
    • APCA Lc +84

Nearest versions that pass 4.5:1

  • For text on white

    #155E75 7.26:1

    It already reaches 7.26:1 on white, so no change is needed.

  • For text on black

    #3A7D95 4.54:1

    Lightening its OKLCH lightness from 0.45 to 0.56 reaches 4.54:1 on black, keeping the hue.

    Compare both in the Contrast System

Checking another pair? Use the Contrast Checker.

Studio

Adjust #155E75 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 #155E75

Eleven OKLCH lightness steps at this hue, each with its contrast against white and black. #155E75 sits at step 700.

  1. 50#E8F8FF
    White
    1.08
    Black
    19.30
  2. 100#D0F2FF
    White
    1.17
    Black
    17.82
  3. 200#A7E2F9
    White
    1.41
    Black
    14.88
  4. 300#8AC8E1
    White
    1.83
    Black
    11.42
  5. 400#6BACC5
    White
    2.52
    Black
    8.33
  6. 500#4E90A9
    White
    3.56
    Black
    5.88
  7. 600#357890
    White
    4.95
    Black
    4.24
  8. 700This color#155E75
    White
    7.26
    Black
    2.88
  9. 800#00475B
    White
    10.23
    Black
    2.05
  10. 900#002E3C
    White
    14.42
    Black
    1.45
  11. 950#001923
    White
    18.05
    Black
    1.16

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

Tailwind CSS v3 cyan scale

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

  1. 50#ECFEFF
    White
    1.04
    Black
    20.18
  2. 100#CFFAFE
    White
    1.11
    Black
    18.75
  3. 200#A5F3FC
    White
    1.24
    Black
    16.82
  4. 300#67E8F9
    White
    1.44
    Black
    14.48
  5. 400#22D3EE
    White
    1.80
    Black
    11.62
  6. 500#06B6D4
    White
    2.42
    Black
    8.64
  7. 600#0891B2
    White
    3.68
    Black
    5.70
  8. 700#0E7490
    White
    5.35
    Black
    3.91
  9. 800This color#155E75
    White
    7.26
    Black
    2.88
  10. 900#164E63
    White
    9.11
    Black
    2.30
  11. 950#083344
    White
    13.39
    Black
    1.56

Gamut

How vivid #155E75 can get

At its lightness and hue, sRGB reaches OKLCH chroma 0.085; #155E75 uses 91% of it. Display P3, which many recent phones and laptops show, reaches 0.112 there: 32% more.

0.00.20.40.60.80.20.40.60.8 460480500520540560580600620
  • sRGB
  • Display P3
  • Rec. 2020
  • Dominant wavelength
OKLCH chroma
0.077
sRGB edge
0.085
Display P3 edge
0.112
Rec. 2020 edge
0.195
Dominant wavelength
484 nm
Excitation purity
42%
Chromaticity
x 0.2135, y 0.2682
  • This color#155E75
  • Most vivid in sRGB#005F78
  • Most vivid in Display P3oklch(0.450 0.112 224.3)

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

Use the wider color where screens show it
.accent {
  color: #155e75;
}
@media (color-gamut: p3) {
  .accent { color: color(display-p3 0 0.3714 0.5007); }
}

Mixing

Mixing #155E75

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%#8AAFBA
  • OKLab50%#8DACB8
  • OKLCH50%#8DACB8

Black #000000

  • sRGB50%#0B2F3B
  • OKLab50%#031F29
  • OKLCH50%#031F29

Its complement #794630

  • sRGB50%#475253
  • OKLab50%#555555
  • OKLCH50%#654873
In CSS
/* A gradient and a mix, worked out in OKLCH */
background: linear-gradient(in oklch, #155e75, white);
color: color-mix(in oklch, #155e75 50%, white);

In use

#155E75 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, 4.5:17.26:1 Passes
  • Link and body-size textText, 4.5:17.26:1 Passes
  • Large headingLarge text, 3:17.26:1 Passes
  • Icons, borders and focus ringsNon-text, 3:17.26:1 Passes

Dark page

  • Button labelText, 4.5:17.26:1 Passes
  • Link and body-size textText, 4.5:12.57:1 Fails
  • Large headingLarge text, 3:12.57:1 Fails
  • Icons, borders and focus ringsNon-text, 3:12.57:1 Fails

For text on this page, the nearest shade that passes is #43869E 4.58:1

Color vision

How #155E75 looks with color blindness

Achromatopsia changes it most, ΔE2000 16.8; tritanopia changes it least, 11.6.

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

    #515C76 ΔE2000 15.0

    Distinct

    Reads as dark grayish blue

  • Deuteranopia

    No working green (medium-wavelength) cones

    #445375 ΔE2000 15.0

    Distinct

    Reads as dark muted blue

  • Tritanopia

    No working blue (short-wavelength) cones

    #006565 ΔE2000 11.6

    Distinct

    Reads as dark muted teal

  • Achromatopsia

    No cone color vision; lightness only

    #575757 ΔE2000 16.8

    Distinct

    Reads as dark gray

Pairing check

Checked against its complement, #794630. Their lightness contrast is only 1.05:1, so where hue collapses, add a label, icon or pattern.

VisionThe pairΔE2000Verdict
Normal vision#155E75 · #79463039.0Stays distinct
Protanopia#515C76 · #534C2E27.8Stays distinct
Deuteranopia#445375 · #60573032.8Stays distinct
Tritanopia#006565 · #843D4144.3Stays distinct
Achromatopsia#575757 · #5353531.4Easily confused

Harmony

Color harmonies for #155E75

Its complement is #794630, a dark muted brown, 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#155E75
  • Complement#794630

Complementary

Open in Harmony Studio
  • −30°#006262
  • Base#155E75
  • +30°#36577F

Analogous

Open in Harmony Studio
  • Base#155E75
  • +120°#734360
  • +240°#5C571E

Triadic

Open in Harmony Studio
  • Base#155E75
  • +150°#7A4248
  • +210°#6E4E1E

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-cyan-800: #155e75;
}

Tailwind config

// tailwind.config.js — already built in as cyan-800;
// pin the v3 value explicitly like this:
module.exports = {
  theme: {
    extend: {
      colors: {
        cyan: { 800: '#155e75' },
      },
    },
  },
};

Tailwind v4 theme

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

@theme {
  /* v4 has its own cyan-800; this pins the v3 value. */
  --color-cyan-800: oklch(0.450 0.077 224.3);
}

Design token (W3C DTCG)

{
  "color": {
    "cyan-800": {
      "$type": "color",
      "$value": {
        "colorSpace": "srgb",
        "components": [0.0824, 0.3686, 0.4588],
        "hex": "#155e75"
      },
      "$description": "Tailwind CSS v3 cyan-800"
    }
  }
}

SwiftUI color

import SwiftUI

enum Palette {
    static let cyan800 = Color(.sRGB, red: 0.082, green: 0.369, blue: 0.459, opacity: 1)
}

Jetpack Compose color

import androidx.compose.ui.graphics.Color

object Palette {
    val Cyan800 = Color(0xFF155E75)
}

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 #155E75 in the tools

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