Tailwind CSS v3 color
Tailwind red-700 #B91C1C
Tailwind CSS v3's red-700 is #B91C1C. It is a vivid red in the red family. In OKLCH it sits at lightness 0.505, chroma 0.190 and hue 27.5°. The nearest CSS named color is firebrick (#B22222), ΔE2000 1.8 away.
- Relative luminance
- 0.1123
- OKLCH L · C · h
- 0.505 · 0.190 · 27.5
- Best text
- White 6.47:1
- Hue family
- Red
#B91C1C color codes
- HEX
#B91C1C- RGB
rgb(185, 28, 28)- HSL
hsl(0, 74%, 42%)- OKLCH
oklch(0.505 0.190 27.5)- OKLab
oklab(0.505 0.169 0.088)- CIELAB (D65)
L* 39.97, a* 59.27, b* 42.19- XYZ (D65)
X 20.64, Y 11.23, Z 2.18- CMYK (naive)
cmyk(0%, 85%, 85%, 27%)
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 #B91C1C accessible?
White text on it reaches 6.47:1, passing AA. Black text manages only 3.24:1, 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
3.24:1
- AA fails
- AA large passes
- AAA fails
- APCA Lc +23
-
White text on it
6.47:1
- AA passes
- AA large passes
- AAA fails
- APCA Lc −85
-
As text on black
3.24:1
- AA fails
- AA large passes
- AAA fails
- APCA Lc −21
-
As text on white
6.47:1
- AA passes
- AA large passes
- AAA fails
- APCA Lc +80
Nearest versions that pass 4.5:1
-
For text on white
#B91C1C 6.47:1
It already reaches 6.47:1 on white, so no change is needed.
-
For text on black
#D53D36 4.54:1
Lightening its OKLCH lightness from 0.51 to 0.59 reaches 4.54:1 on black, keeping the hue.
Checking another pair? Use the Contrast Checker.
Studio
Adjust #B91C1C 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.
Scale
Shades and tints of #B91C1C
Eleven OKLCH lightness steps at this hue, each with its contrast against white and black. #B91C1C sits at step 600.
Under each step, white and black text on it; a bold figure passes 4.5:1.
Tailwind CSS v3 red scale
The real Tailwind palette, for comparison with the computed ramp above.
Gamut
How vivid #B91C1C can get
At its lightness and hue, sRGB reaches OKLCH chroma 0.206; #B91C1C uses 92% of it. Display P3, which many recent phones and laptops show, reaches 0.233 there: 13% more.
- sRGB
- Display P3
- Rec. 2020
- Dominant wavelength
- OKLCH chroma
- 0.190
- sRGB edge
- 0.206
- Display P3 edge
- 0.233
- Rec. 2020 edge
- 0.242
- Dominant wavelength
- 611 nm
- Excitation purity
- 82%
- Chromaticity
- x 0.6061, y 0.3299
- This color#B91C1C
- Most vivid in sRGB#BF000F
- Most vivid in Display P3oklch(0.505 0.233 27.5)
On a screen without Display P3 the last tile shows the sRGB edge instead.
.accent {
color: #b91c1c;
}
@media (color-gamut: p3) {
.accent { color: color(display-p3 0.7167 0 0.0483); }
}Mixing
Mixing #B91C1C
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%#DC8E8E
- OKLab50%#E5978E
- OKLCH50%#E5978E
Black #000000
- sRGB50%#5D0E0E
- OKLab50%#460505
- OKLCH50%#460505
Its complement #00727E
- sRGB50%#5D474D
- OKLab50%#805954
- OKLCH50%#6F4FA9
/* A gradient and a mix, worked out in OKLCH */
background: linear-gradient(in oklch, #b91c1c, white);
color: color-mix(in oklch, #b91c1c 50%, white);In use
#B91C1C 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, 4.5:16.47:1 Passes
- Link and body-size textText, 4.5:16.47:1 Passes
- Large headingLarge text, 3:16.47:1 Passes
- Icons, borders and focus ringsNon-text, 3:16.47:1 Passes
Dark page
- Button labelText, 4.5:16.47:1 Passes
- Link and body-size textText, 4.5:12.89:1 Fails
- Large headingLarge text, 3:12.89:1 Fails
- Icons, borders and focus ringsNon-text, 3:12.89:1 Fails
For text on this page, the nearest shade that passes is #DE463D 4.50:1
Color vision
How #B91C1C looks with color blindness
Deuteranopia changes it most, ΔE2000 39.0; tritanopia changes it least, 3.5.
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
#524919 ΔE2000 35.2
Distinct
Reads as dark muted brown
-
Deuteranopia
No working green (medium-wavelength) cones
#776A12 ΔE2000 39.0
Distinct
Reads as soft yellow
-
Tritanopia
No working blue (short-wavelength) cones
#CC001F ΔE2000 3.5
Close match
Reads as vivid red
-
Achromatopsia
No cone color vision; lightness only
#5E5E5E ΔE2000 27.7
Distinct
Reads as dark gray
Pairing check
Checked against its complement, #00727E. Their lightness contrast is only 1.14:1, so where hue collapses, add a label, icon or pattern.
| Vision | The pair | ΔE2000 | Verdict |
|---|---|---|---|
| Normal vision | #B91C1C · #00727E | 49.3 | Stays distinct |
| Protanopia | #524919 · #676D7F | 31.2 | Stays distinct |
| Deuteranopia | #776A12 · #58627E | 38.4 | Stays distinct |
| Tritanopia | #CC001F · #007876 | 55.6 | Stays distinct |
| Achromatopsia | #5E5E5E · #676767 | 3.3 | Easily confused |
Harmony
Color harmonies for #B91C1C
Its complement is #00727E, a muted teal, on the cool 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#B91C1C
- Complement#00727E
Complementary
Open in Harmony Studio- −30°#B11A65
- Base#B91C1C
- +30°#974F00
Analogous
Open in Harmony Studio- Base#B91C1C
- +120°#007A2C
- +240°#3657D0
Triadic
Open in Harmony Studio- Base#B91C1C
- +150°#007664
- +210°#006C9C
Split-complementary
Open in Harmony StudioCode
Design tokens
Ready-to-paste tokens in six formats. Rename them to fit your system.
:root {
--color-red-700: #b91c1c;
}// tailwind.config.js — already built in as red-700;
// pin the v3 value explicitly like this:
module.exports = {
theme: {
extend: {
colors: {
red: { 700: '#b91c1c' },
},
},
},
};/* app.css — Tailwind CSS v4 */
@import "tailwindcss";
@theme {
/* v4 has its own red-700; this pins the v3 value. */
--color-red-700: oklch(0.505 0.190 27.5);
}{
"color": {
"red-700": {
"$type": "color",
"$value": {
"colorSpace": "srgb",
"components": [0.7255, 0.1098, 0.1098],
"hex": "#b91c1c"
},
"$description": "Tailwind CSS v3 red-700"
}
}
}import SwiftUI
enum Palette {
static let red700 = Color(.sRGB, red: 0.725, green: 0.110, blue: 0.110, opacity: 1)
}import androidx.compose.ui.graphics.Color
object Palette {
val Red700 = Color(0xFFB91C1C)
}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 #B91C1C in the tools
Each opens over this page. More colors live in the Color Library, and every color page is listed on the hub.
- Color InspectorEvery format, its names, contrast and color vision in one panel.
- Contrast SystemBlack and white text on this color, with fixes in both directions.
- Harmony StudioPalettes built from this color, walked to a contrast target if you ask.
- Color Space ConverterThe same color in 34 notations, with its gamut headroom.
- Color Name FinderThe nearest of 1,055 color names by ΔE2000.