Red4
red4 · #8B0000
HEX
#8B0000
RGB
rgb(139, 0, 0)
CMYK
cmyk(0%, 100%, 100%, 45%)
HSL
hsl(0, 100%, 27%)
LAB
lab(28.1, 51.0, 41.3)
What is Red4?
Red4 is the red4 reference in the X11 named colors. Its sRGB value is #8B0000 (rgb 139, 0, 0). It sits in the red family. Historical X Window System color names — the numbered 1-4 lightness variants of the classic xorg-server rgb.txt palette. See disclaimer for accuracy and trademark notes.
Accessibility
WCAG 2.1 contrast checks for Red4 as a background.
Black text on this color
White text on this color
Shades, tints & tonal scale of Red4
An 11-step tonal scale derived from Red4 (#8B0000). Click any swatch to copy its HEX. Use these as a starting point for design tokens, hover states, and disabled states in a design system.
50
#F6EBEB
#F6EBEB
100
#ECD6D6
#ECD6D6
200
#DAADAD
#DAADAD
300
#C58080
#C58080
400
#A84040
#A84040
500
#8B0000
#8B0000
600
#760000
#760000
700
#5A0000
#5A0000
800
#3F0000
#3F0000
900
#230000
#230000
950
#110000
#110000
Lighter tints (mixed with white)
15%
#A46C6C
30%
#B89595
45%
#CAB3B3
60%
#DACBCB
75%
#E9E1E1
Darker shades (mixed with black)
15%
#810000
30%
#760000
45%
#690000
60%
#5A0000
75%
#480000
Color harmonies for Red4
Classic color-theory harmonies derived from rotating the hue of Red4. Use these to build accent palettes, brand systems, and accessible UI color pairings.
Complementary
180° opposite — strongest contrast
#8B0000
#8B0000
#008A8A
#008A8A
Triadic
Three colors 120° apart
#8B0000
#8B0000
#008A00
#008A00
#00008A
#00008A
Analogous
Two neighbors ±30° on the wheel
#8A0045
#8A0045
#8B0000
#8B0000
#8A4500
#8A4500
Split-complementary
Base + two colors flanking its complement
#8B0000
#8B0000
#008A45
#008A45
#00458A
#00458A
Tetradic
Two complementary pairs
#8B0000
#8B0000
#8A8A00
#8A8A00
#008A8A
#008A8A
#00008A
#00008A
Square
Four colors evenly spaced 90° apart
#8B0000
#8B0000
#458A00
#458A00
#008A8A
#008A8A
#45008A
#45008A
Red4 in every color space
Full conversion of Red4 across the color spaces designers and developers actually use — including OKLCH (the perceptually-uniform space that powers Tailwind v4 and CSS Color Module Level 4) and HWB.
HEX
#8B0000
RGB
rgb(139, 0, 0)
CMYK
cmyk(0%, 100%, 100%, 45%)
HSL
hsl(0, 100%, 27%)
HSV
hsv(0, 100%, 55%)
HWB
hwb(0 0% 45%)
CIE Lab
lab(28.1 51.0 41.3)
OKLCH
oklch(40.0% 0.164 29.2)
XYZ (D65)
xyz(10.65, 5.49, 0.50)
Copy-ready code for Red4
Drop-in snippets for CSS, Tailwind, Sass, iOS Swift, and Android XML. Click the copy button on any snippet to put it on your clipboard.
CSS
color: #8B0000;
background-color: #8B0000;CSS variable
:root {
--color-red4: #8B0000;
}Tailwind config
// tailwind.config.js
colors: {
'red4': '#8B0000',
}Sass
$color-red4: #8B0000;Swift UIColor
UIColor(red: 0.545, green: 0.000, blue: 0.000, alpha: 1.0)Android XML
<color name="red4">#8B0000</color>Closest match in every color system
The nearest Red4 equivalent in every other color system on this site, ranked by ΔE2000 perceptual distance. Useful when translating between design-system, web-standard, and industrial color references.
Closest in X11 named colors
Top 6 ΔE2000-closest entries within the same collection.
Closest Pantone matches
Top 6 ΔE2000-closest Pantone references. Cross-system matching is approximate — see disclaimer.
Closest RAL Classic matches
Top 6 ΔE2000-closest RAL Classic references for industrial coating cross-reference.
RAL 3013
#A12312
Tomato red
RAL 3011
#781F19
Brown red
RAL 3003
#9B111E
Ruby red
RAL 3001
#A52019
Signal red
RAL 3002
#A2231D
Carmine red
RAL 3004
#75151E
Purple red
FAQ about Red4
What is the HEX code for Red4?
Red4 (red4) has the HEX code #8B0000. In RGB it is rgb(139, 0, 0), and in CMYK it is cmyk(0%, 100%, 100%, 45%).
What is the OKLCH value of Red4?
Red4 converts to oklch(0.400 0.164 29.2). OKLCH is the perceptually uniform color space used by Tailwind v4 and CSS Color Module Level 4.
Is Red4 accessible for body text?
Used as a background, Red4 has a contrast ratio of 2.10:1 with black text and 10.01:1 with white text. WCAG 2.1 AA requires 4.5:1 for normal text. The current recommendation is to use white text and verify in real UI context.
What is the closest Pantone to Red4?
The closest Pantone reference to Red4 by ΔE2000 perceptual distance is Pantone 174 C (#963821). Cross-system Pantone matching is approximate; for color-critical print work, verify with a physical Pantone guide.
What is the closest RAL color to Red4?
The closest RAL Classic reference to Red4 by ΔE2000 distance is RAL 3013 (Tomato red, #A12312). RAL is a German industrial coating standard commonly used for paint, powder coat, and architectural specification.
What is the complementary color of Red4?
The complementary color (180° opposite on the HSL color wheel) of Red4 is #008A8A. Use it for high-contrast accents, error states, or call-to-action pairings.
Data provenance & source
X11 named colors (xorg rgb.txt)
The historical X11 color name list shipped in the xorg-server rgb.txt file. Roughly 550 entries covering classic computing color names like 'PapayaWhip', 'MediumAquamarine', and 'DarkSlateGray'. Many CSS named colors originate here. Use as a reference for legacy and creative color names. Most modern CSS implementations accept these names directly.
- Source type
- derived
- Confidence
- high
- License
- MIT/X11 license (X Consortium)
- Last reviewed
- 2026-05-24
Workflow tags
X11 colors are sRGB digital values from a 1980s color system. For print, convert to a process-appropriate color and proof against substrate.