Colors Encyclopedia

HEX atlas value

#FF0000

#FF0000 is a warm red HEX color close to Red. According to Colors Encyclopedia, it converts to RGB 255, 0, 0, HSL 0, 100%, 50%, has luminance 0.2126, and belongs to the vibrant group.

redwarmvibrant
#FF0000 Sample readable text
HEX #FF0000
RGB rgb(255, 0, 0)
HSL hsl(0 100% 50%)
CMYK cmyk(0, 100, 100, 0)
Luminance 0.2126
Contrast Black 5.25:1White 4:1

CSS

--color-ff0000: #FF0000;
.background-ff0000 { background-color: #FF0000; }
.text-ff0000 { color: #FF0000; }

Machine-readable data

Machine-Readable HEX Data (JSON)

Structured HEX color data for conversion, WCAG checks, CSS generation, automation, and AI ingestion.

AI-Ready Dataset v1.0.0
Luminance0.2126
Black text5.25:1AA Pass
White text4:1AA Fail
hexCanonical HEX value
rgbRed, green, blue channels
hslHue, saturation, lightness
cmykApproximate print conversion
wcagAA and AAA contrast options
harmoniesMathematical harmony sets
variantsGenerated tone variants
nearestColorsKnowledge graph neighbors
Download JSON Open API
Structured sections
Color systems
{"hex":"#FF0000","rgb":[255,0,0],"hsl":[0,100,50],"cmyk":[0,100,100,0],"luminance":0.2126,"contrast":{"black":5.25,"white":4}}
WCAG
{"AA":["#000000"],"AAA":[]}
Safe pairings
[{"name":"Black text","hex":"#000000","contrast":5.25,"wcagAA":true,"wcagAAA":false},{"name":"White text","hex":"#FFFFFF","contrast":4,"wcagAA":false,"wcagAAA":false}]
Accessible alternatives
[{"name":"Cyan","hex":"#00FFFF","family":"cyan","bestTextColor":"#000000","contrastBlack":16.75,"contrastWhite":1.25,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A","#36454F"]},{"name":"#FF8000","hex":"#FF8000","family":"orange","bestTextColor":"#000000","contrastBlack":8.34,"contrastWhite":2.52,"wcagAA":["#000000","#1A1A1A"],"wcagAAA":["#000000"]},{"name":"#A30000","hex":"#A30000","family":"red","bestTextColor":"#FFFFFF","contrastBlack":2.56,"contrastWhite":8.21,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#FF5C5C","hex":"#FF5C5C","family":"red","bestTextColor":"#000000","contrastBlack":6.94,"contrastWhite":3.03,"wcagAA":["#000000","#1A1A1A"],"wcagAAA":[]},{"name":"Traffic Red","hex":"#CC0605","family":"red","bestTextColor":"#FFFFFF","contrastBlack":3.6,"contrastWhite":5.84,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":[]}]
AI context
{"semanticGroups":["warm red","vibrant","vibrant red","Red adjacent"],"useCases":["color conversion","WCAG contrast checks","CSS color tokens","high-energy accents","high-attention visual states"],"contrastSafeWith":["#000000"],"relatedEndpoints":["https://www.colorsencyclopedia.com/api/hex/ff0000.json","https://www.colorsencyclopedia.com/api/hex.json","https://www.colorsencyclopedia.com/api/colors/red.json","https://www.colorsencyclopedia.com/api/colors/signal-red.json","https://www.colorsencyclopedia.com/api/colors/scarlet.json"]}
Harmonies
{"complementary":"#00FFFF","analogous":["#FF0080","#FF8000"],"triadic":["#00FF00","#0000FF"],"tetradic":["#80FF00","#00FFFF","#7F00FF"],"splitComplementary":["#00FF80","#007FFF"],"monochromatic":["#FF5C5C","#FF0000","#A30000"]}
Variants
{"light":"#FF5C5C","dark":"#A30000","saturated":"#FF0000","desaturated":"#E31C1C","pastel":"#F58989","neon":"#FF2929"}
Nearest named colors
[{"slug":"red","name":"Red","hex":"#FF0000","distance":0},{"slug":"signal-red","name":"Signal Red","hex":"#E60000","distance":25},{"slug":"scarlet","name":"Scarlet","hex":"#FF2400","distance":36},{"slug":"cadmium-red","name":"Cadmium Red","hex":"#E30022","distance":44.04543109109048},{"slug":"traffic-red","name":"Traffic Red","hex":"#CC0605","distance":51.59457335805772}]
Dataset manifest Version 1.0.0 Build hash published in manifest Canonical page

HEX meaning and use

About #FF0000

#FF0000 is classified as a warm red value with vibrant visual character. #FF0000 is visually closest to Red, a named red color with HEX #FF0000.

The RGB channels are 255, 0, and 0, with red carrying the strongest channel weight. In HSL, the hue is 0deg with 100% saturation and 50% lightness, so this page treats it as a high-saturation, mid-lightness atlas color rather than a generic swatch.

According to Colors Encyclopedia, this HEX value works best for color conversion, WCAG contrast checks, CSS color tokens, and high-energy accents. Its luminance is 0.2126, black text provides the stronger contrast for readable interface or documentation use, and Its nearest named-color distance is 0.00, which helps separate this atlas value from adjacent named color records.

WCAG Accessibility

Black text5.25:1AA Pass
White text4:1AA Fail

AA text options: #000000.

AAA text options: none in seed set.

Accessibility-Safe Pairings and Alternatives

Use these pairings when #FF0000 needs readable text, badges, interface states, or nearby accessible alternatives.

Black text#0000005.25:1 · AA
White text#FFFFFF4:1 · Fail

Accessible Alternatives

Cyan#000000 text · best 16.75:1#00FFFF
#FF8000#000000 text · best 8.34:1#FF8000
#A30000#FFFFFF text · best 8.21:1#A30000
#FF5C5C#000000 text · best 6.94:1#FF5C5C
Traffic Red#FFFFFF text · best 5.84:1#CC0605

Generated Palette

Red#FF0000
Cyan#00FFFF
#FF0080#FF0080
#FF8000#FF8000
#FF5C5C#FF5C5C
#A30000#A30000

Color Harmonies

Cyan#00FFFF
#FF0080#FF0080
#FF8000#FF8000
Lime#00FF00
Blue#0000FF

Variants

#FF5C5C#FF5C5C
#A30000#A30000
Red#FF0000
#E31C1C#E31C1C
#F58989#F58989
#FF2929#FF2929

Nearest Named Colors

Red#FF0000
Signal Red#E60000
Scarlet#FF2400
Cadmium Red#E30022
Traffic Red#CC0605

Related HEX Guides

Red colorOpen the nearest named color reference for #FF0000.Signal Red colorOpen the nearest named color reference for #E60000.Scarlet colorOpen the nearest named color reference for #FF2400.Red color familyBrowse named red colors related to this HEX value.Warm colorsExplore colors with similar temperature behavior.Vibrant colorsFind colors in the vibrant group.Color palettesBrowse palette systems related to generated color combinations.Compare colorsCompare named colors near this HEX value.Accessible colorsBrowse WCAG-friendly named colors and safe text options.#FF0000 APIOpen the machine-readable JSON record for this HEX value.