Red1
red1 · #FF0000
HEX
#FF0000
RGB
rgb(255, 0, 0)
CMYK
cmyk(0%, 100%, 100%, 0%)
HSL
hsl(0, 100%, 50%)
LAB
lab(53.2, 80.1, 67.2)
What is Red1?
Red1 is the red1 reference in the X11 named colors. Its sRGB value is #FF0000 (rgb 255, 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 Red1 as a background.
Black text on this color
White text on this color
Shades, tints & tonal scale of Red1
An 11-step tonal scale derived from Red1 (#FF0000). 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
#FFEBEB
#FFEBEB
100
#FFD6D6
#FFD6D6
200
#FFADAD
#FFADAD
300
#FF8080
#FF8080
400
#FF4040
#FF4040
500
#FF0000
#FF0000
600
#D90000
#D90000
700
#A60000
#A60000
800
#730000
#730000
900
#400000
#400000
950
#1F0000
#1F0000
Lighter tints (mixed with white)
15%
#FF6C6C
30%
#FF9595
45%
#FFB3B3
60%
#FFCBCB
75%
#FFE1E1
Darker shades (mixed with black)
15%
#ED0000
30%
#DA0000
45%
#C40000
60%
#AA0000
75%
#890000
Color harmonies for Red1
Classic color-theory harmonies derived from rotating the hue of Red1. Use these to build accent palettes, brand systems, and accessible UI color pairings.
Complementary
180° opposite — strongest contrast
#FF0000
#FF0000
#00FFFF
#00FFFF
Triadic
Three colors 120° apart
#FF0000
#FF0000
#00FF00
#00FF00
#0000FF
#0000FF
Analogous
Two neighbors ±30° on the wheel
#FF0080
#FF0080
#FF0000
#FF0000
#FF8000
#FF8000
Split-complementary
Base + two colors flanking its complement
#FF0000
#FF0000
#00FF80
#00FF80
#007FFF
#007FFF
Tetradic
Two complementary pairs
#FF0000
#FF0000
#FFFF00
#FFFF00
#00FFFF
#00FFFF
#0000FF
#0000FF
Square
Four colors evenly spaced 90° apart
#FF0000
#FF0000
#80FF00
#80FF00
#00FFFF
#00FFFF
#7F00FF
#7F00FF
Red1 in every color space
Full conversion of Red1 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
#FF0000
RGB
rgb(255, 0, 0)
CMYK
cmyk(0%, 100%, 100%, 0%)
HSL
hsl(0, 100%, 50%)
HSV
hsv(0, 100%, 100%)
HWB
hwb(0 0% 0%)
CIE Lab
lab(53.2 80.1 67.2)
OKLCH
oklch(62.8% 0.258 29.2)
XYZ (D65)
xyz(41.25, 21.27, 1.93)
Copy-ready code for Red1
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: #FF0000;
background-color: #FF0000;CSS variable
:root {
--color-red1: #FF0000;
}Tailwind config
// tailwind.config.js
colors: {
'red1': '#FF0000',
}Sass
$color-red1: #FF0000;Swift UIColor
UIColor(red: 1.000, green: 0.000, blue: 0.000, alpha: 1.0)Android XML
<color name="red1">#FF0000</color>Closest match in every color system
The nearest Red1 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 2009
#F54021
Traffic orange
RAL 2004
#F44611
Pure orange
RAL 2012
#E55137
Salmon orange
RAL 2010
#D84B20
Signal orange
RAL 3022
#D95030
Salmon pink
RAL 2008
#F75E25
Bright red orange
FAQ about Red1
What is the HEX code for Red1?
Red1 (red1) has the HEX code #FF0000. In RGB it is rgb(255, 0, 0), and in CMYK it is cmyk(0%, 100%, 100%, 0%).
What is the OKLCH value of Red1?
Red1 converts to oklch(0.628 0.258 29.2). OKLCH is the perceptually uniform color space used by Tailwind v4 and CSS Color Module Level 4.
Is Red1 accessible for body text?
Used as a background, Red1 has a contrast ratio of 5.25:1 with black text and 4.00:1 with white text. WCAG 2.1 AA requires 4.5:1 for normal text. The current recommendation is to use black text and verify in real UI context.
What is the closest Pantone to Red1?
The closest Pantone reference to Red1 by ΔE2000 perceptual distance is Pantone 172 C (#FA4616). Cross-system Pantone matching is approximate; for color-critical print work, verify with a physical Pantone guide.
What is the closest RAL color to Red1?
The closest RAL Classic reference to Red1 by ΔE2000 distance is RAL 2009 (Traffic orange, #F54021). RAL is a German industrial coating standard commonly used for paint, powder coat, and architectural specification.
What is the complementary color of Red1?
The complementary color (180° opposite on the HSL color wheel) of Red1 is #00FFFF. 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.