HEX atlas value

#A51D09

#A51D09 is a warm red HEX color close to Pompeian Red. According to Colors Encyclopedia, it converts to RGB 165, 29, 9, HSL 8, 90%, 34%, has luminance 0.089, and belongs to the balanced group.

red warm balanced

#A51D09 Sample readable text

HEX #A51D09

RGB rgb(165, 29, 9)

HSL hsl(8 90% 34%)

CMYK cmyk(0, 82, 95, 35)

Luminance 0.089

Contrast Black 2.78:1White 7.55:1

CSS

--color-a51d09: #A51D09;
.background-a51d09 { background-color: #A51D09; }
.text-a51d09 { color: #A51D09; }

Luminance0.089

Black text2.78:1AA Fail

White text7.55:1AA Pass

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

Structured sections

Color systems

{"hex":"#A51D09","rgb":[165,29,9],"hsl":[8,90,34],"cmyk":[0,82,95,35],"luminance":0.089,"contrast":{"black":2.78,"white":7.55}}

WCAG

{"AA":["#FFFFFF","#F5F5F5"],"AAA":["#FFFFFF"]}

Safe pairings

[{"name":"Black text","hex":"#000000","contrast":2.78,"wcagAA":false,"wcagAAA":false},{"name":"White text","hex":"#FFFFFF","contrast":7.55,"wcagAA":true,"wcagAAA":true}]

Accessible alternatives

[{"name":"#4E0E04","hex":"#4E0E04","family":"red","bestTextColor":"#FFFFFF","contrastBlack":1.39,"contrastWhite":15.13,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"Crimson Red","hex":"#990000","family":"red","bestTextColor":"#FFFFFF","contrastBlack":2.35,"contrastWhite":8.92,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"Cranberry","hex":"#9F000F","family":"red","bestTextColor":"#FFFFFF","contrastBlack":2.48,"contrastWhite":8.46,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"Ruby Red","hex":"#9B111E","family":"red","bestTextColor":"#FFFFFF","contrastBlack":2.49,"contrastWhite":8.43,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#922B1C","hex":"#922B1C","family":"red","bestTextColor":"#FFFFFF","contrastBlack":2.58,"contrastWhite":8.13,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]}]

AI context

{"semanticGroups":["warm red","balanced","balanced red","Pompeian Red adjacent"],"useCases":["color conversion","WCAG contrast checks","CSS color tokens","high-attention visual states"],"contrastSafeWith":["#FFFFFF","#F5F5F5"],"relatedEndpoints":["https://www.colorsencyclopedia.com/api/hex/a51d09.json","https://www.colorsencyclopedia.com/api/hex.json","https://www.colorsencyclopedia.com/api/colors/pompeian-red.json","https://www.colorsencyclopedia.com/api/colors/ruby-red.json","https://www.colorsencyclopedia.com/api/colors/firebrick.json"]}

Harmonies

{"complementary":"#0990A5","analogous":["#A50942","#A56C09"],"triadic":["#09A51D","#1D09A5"],"tetradic":["#42A509","#0990A5","#6C09A5"],"splitComplementary":["#09A56C","#0942A5"],"monochromatic":["#F33416","#A51D09","#4E0E04"]}

Variants

{"light":"#F33416","dark":"#4E0E04","saturated":"#AD1700","desaturated":"#922B1C","pastel":"#E55D48","neon":"#D61D00"}

Nearest named colors

[{"slug":"pompeian-red","name":"Pompeian Red","hex":"#A42A04","distance":13.96424004376894},{"slug":"ruby-red","name":"Ruby Red","hex":"#9B111E","distance":26.1725046566048},{"slug":"firebrick","name":"Firebrick","hex":"#B22222","distance":28.61817604250837},{"slug":"cranberry","name":"Cranberry","hex":"#9F000F","distance":30.215889859476256},{"slug":"crimson-red","name":"Crimson Red","hex":"#990000","distance":32.64965543462902}]

HEX meaning and use

About #A51D09

#A51D09 is classified as a warm red value with balanced visual character. #A51D09 is visually closest to Pompeian Red, a named red color with HEX #A42A04.

The RGB channels are 165, 29, and 9, with red carrying the strongest channel weight. In HSL, the hue is 8deg with 90% saturation and 34% 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-attention visual states. Its luminance is 0.089, white text provides the stronger contrast for readable interface or documentation use, and Its nearest named-color distance is 13.96, which helps separate this atlas value from adjacent named color records.

WCAG Accessibility

Black text2.78:1AA Fail

White text7.55:1AA Pass

AA text options: #FFFFFF, #F5F5F5.

AAA text options: #FFFFFF.

Accessibility-Safe Pairings and Alternatives

Use these pairings when #A51D09 needs readable text, badges, interface states, or nearby accessible alternatives.

Black text#0000002.78:1 · Fail

White text#FFFFFF7.55:1 · AAA

Accessible Alternatives

#4E0E04#FFFFFF text · best 15.13:1#4E0E04

Crimson Red#FFFFFF text · best 8.92:1#990000

Cranberry#FFFFFF text · best 8.46:1#9F000F

Ruby Red#FFFFFF text · best 8.43:1#9B111E

#922B1C#FFFFFF text · best 8.13:1#922B1C

Generated Palette

#A51D09#A51D09

#0990A5#0990A5

#A50942#A50942

#A56C09#A56C09

#F33416#F33416

#4E0E04#4E0E04

Color Harmonies

#0990A5#0990A5

#A50942#A50942

#A56C09#A56C09

#09A51D#09A51D

#1D09A5#1D09A5

Variants

#F33416#F33416

#4E0E04#4E0E04

#AD1700#AD1700

#922B1C#922B1C

#E55D48#E55D48

#D61D00#D61D00

Nearest Named Colors

Pompeian Red#A42A04

Ruby Red#9B111E

Firebrick#B22222

Cranberry#9F000F

Crimson Red#990000

#A51D09

CSS

Machine-Readable HEX Data (JSON)

About #A51D09

WCAG Accessibility

Accessibility-Safe Pairings and Alternatives

Accessible Alternatives

Generated Palette

Color Harmonies

Variants

Nearest Named Colors

Related HEX Guides