Tailwind CSS v3 color

Tailwind cyan-50 #ECFEFF

Tailwind CSS v3's cyan-50 is #ECFEFF. It is an off-white in the neutral family. In OKLCH it sits at lightness 0.984 with chroma 0.019, too low for hue to matter. The nearest CSS named color is azure (#F0FFFF), ΔE2000 1.1 away.

Relative luminance
0.9594
OKLCH L · C · h
0.984 · 0.019 · 200.9
Best text
Black 20.18:1
Hue family
Neutral

#ECFEFF color codes

HEX
#ECFEFF
RGB
rgb(236, 254, 255)
HSL
hsl(183, 100%, 96%)
OKLCH
oklch(0.984 0.019 200.9)
OKLab
oklab(0.984 -0.018 -0.007)
CIELAB (D65)
L* 98.41, a* -5.66, b* -2.49
XYZ (D65)
X 88.08, Y 95.94, Z 108.47
CMYK (naive)
cmyk(7%, 0%, 0%, 0%)

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 #ECFEFF accessible?

Black text on it reaches 20.18:1, passing AAA. White text fails at 1.04:1.

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

    20.18:1

    • AA passes
    • AA large passes
    • AAA passes
    • APCA Lc +103
  • White text on it

    1.04:1

    • AA fails
    • AA large fails
    • AAA fails
    • APCA Lc 0

    Text is here, unreadable at 1.04:1

  • As text on black

    20.18:1

    • AA passes
    • AA large passes
    • AAA passes
    • APCA Lc −104
  • As text on white

    1.04:1

    • AA fails
    • AA large fails
    • AAA fails
    • APCA Lc 0

    Text is here, unreadable at 1.04:1

Nearest versions that pass 4.5:1

  • For text on white

    #69797A 4.54:1

    Darkening its OKLCH lightness from 0.98 to 0.56 reaches 4.54:1 on white, keeping the hue.

  • For text on black

    #ECFEFF 20.18:1

    It already reaches 20.18:1 on black, so no change is needed.

Checking another pair? Use the Contrast Checker.

Studio

Adjust #ECFEFF 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 #ECFEFF

Eleven OKLCH lightness steps at this hue, each with its contrast against white and black. #ECFEFF sits at step 50.

  1. 50This color#ECFEFF
    White
    1.04
    Black
    20.18
  2. 100#E0EFEF
    White
    1.18
    Black
    17.76
  3. 200#CCDBDC
    White
    1.42
    Black
    14.73
  4. 300#B1C1C2
    White
    1.86
    Black
    11.27
  5. 400#95A5A6
    White
    2.55
    Black
    8.21
  6. 500#7A8A8B
    White
    3.59
    Black
    5.83
  7. 600#627273
    White
    5.03
    Black
    4.17
  8. 700#4D5B5C
    White
    7.07
    Black
    2.96
  9. 800#354343
    White
    10.31
    Black
    2.03
  10. 900#202B2C
    White
    14.54
    Black
    1.44
  11. 950#0E1819
    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. 50This color#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. 800#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 #ECFEFF can get

A gray has no hue, so no gamut holds a more vivid version of #ECFEFF: more chroma would make it another color.

0.00.20.40.60.80.20.40.60.8 460480500520540560580600620
  • sRGB
  • Display P3
  • Rec. 2020
  • Dominant wavelength
OKLCH chroma
0.019
sRGB edge
No hue
Display P3 edge
No hue
Rec. 2020 edge
No hue
Dominant wavelength
490 nm
Excitation purity
4%
Chromaticity
x 0.3011, y 0.3280

Mixing

Mixing #ECFEFF

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%#F6FFFF
  • OKLab50%#F6FFFF
  • OKLCH50%#F6FFFF

Black #000000

  • sRGB50%#767F80
  • OKLab50%#5B6363
  • OKLCH50%#5B6363
In CSS
/* A gradient and a mix, worked out in OKLCH */
background: linear-gradient(in oklch, #ecfeff, white);
color: color-mix(in oklch, #ecfeff 50%, white);

In use

#ECFEFF 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, 4.5:120.18:1 Passes
  • Link and body-size textText, 4.5:11.04:1 Fails
  • Large headingLarge text, 3:11.04:1 Fails
  • Icons, borders and focus ringsNon-text, 3:11.04:1 Fails

For text on this page, the nearest shade that passes is #69797A 4.54:1

Dark page

  • Button labelText, 4.5:120.18:1 Passes
  • Link and body-size textText, 4.5:118.00:1 Passes
  • Large headingLarge text, 3:118.00:1 Passes
  • Icons, borders and focus ringsNon-text, 3:118.00:1 Passes

Color vision

How #ECFEFF looks with color blindness

As a neutral it barely changes under any simulation, ΔE2000 7.7 at most.

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

    #FBFCFF ΔE2000 7.4

    Noticeable

    Reads as white

  • Deuteranopia

    No working green (medium-wavelength) cones

    #F7F9FF ΔE2000 7.7

    Noticeable

    Reads as off-white

  • Tritanopia

    No working blue (short-wavelength) cones

    #E7FFFE ΔE2000 2.4

    Close match

    Reads as pale grayish cyan

  • Achromatopsia

    No cone color vision; lightness only

    #FAFAFA ΔE2000 7.4

    Noticeable

    Reads as white

Pairing check

A near-neutral has no complementary hue to pair with, so tell it apart from neighboring grays by lightness contrast alone.

Harmony

Color harmonies for #ECFEFF

A neutral has no hue to rotate, so every harmony collapses back to the same gray. Pair it with an accent color instead.

Or pair it by lightness: steps of its own scale as text on it, and what each can carry.

Build a lightness scale in Harmony Studio
  • Step 950 #0E1819 · 17.35:1

    Body text, AAA

  • Step 700 #4D5B5C · 6.80:1

    Body text, AA

  • Step 300 #B1C1C2 · 1.79:1

    Decoration only, under 3:1

Code

Design tokens

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

CSS custom property

:root {
  --color-cyan-50: #ecfeff;
}

Tailwind config

// tailwind.config.js — already built in as cyan-50;
// pin the v3 value explicitly like this:
module.exports = {
  theme: {
    extend: {
      colors: {
        cyan: { 50: '#ecfeff' },
      },
    },
  },
};

Tailwind v4 theme

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

@theme {
  /* v4 has its own cyan-50; this pins the v3 value. */
  --color-cyan-50: oklch(0.984 0.019 200.9);
}

Design token (W3C DTCG)

{
  "color": {
    "cyan-50": {
      "$type": "color",
      "$value": {
        "colorSpace": "srgb",
        "components": [0.9255, 0.9961, 1],
        "hex": "#ecfeff"
      },
      "$description": "Tailwind CSS v3 cyan-50"
    }
  }
}

SwiftUI color

import SwiftUI

enum Palette {
    static let cyan50 = Color(.sRGB, red: 0.925, green: 0.996, blue: 1.000, opacity: 1)
}

Jetpack Compose color

import androidx.compose.ui.graphics.Color

object Palette {
    val Cyan50 = Color(0xFFECFEFF)
}

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 #ECFEFF in the tools

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