Colors Encyclopedia

HEX atlas value

#664C47

#664C47 is a warm red HEX color close to Umber. According to Colors Encyclopedia, it converts to RGB 102, 76, 71, HSL 10, 18%, 34%, has luminance 0.0845, and belongs to the muted group.

redwarmmuted
#664C47 Sample readable text
HEX #664C47
RGB rgb(102, 76, 71)
HSL hsl(10 18% 34%)
CMYK cmyk(0, 25, 30, 60)
Luminance 0.0845
Contrast Black 2.69:1White 7.81:1

CSS

--color-664c47: #664C47;
.background-664c47 { background-color: #664C47; }
.text-664c47 { color: #664C47; }

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
Luminance0.0845
Black text2.69:1AA Fail
White text7.81:1AA 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
Download JSON Open API
Structured sections
Color systems
{"hex":"#664C47","rgb":[102,76,71],"hsl":[10,18,34],"cmyk":[0,25,30,60],"luminance":0.0845,"contrast":{"black":2.69,"white":7.81}}
WCAG
{"AA":["#FFFFFF","#F5F5F5"],"AAA":["#FFFFFF","#F5F5F5"]}
Safe pairings
[{"name":"Black text","hex":"#000000","contrast":2.69,"wcagAA":false,"wcagAAA":false},{"name":"White text","hex":"#FFFFFF","contrast":7.81,"wcagAA":true,"wcagAAA":true}]
Accessible alternatives
[{"name":"#302421","hex":"#302421","family":"red","bestTextColor":"#FFFFFF","contrastBlack":1.4,"contrastWhite":15,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"Walnut","hex":"#5C4033","family":"orange","bestTextColor":"#FFFFFF","contrastBlack":2.24,"contrastWhite":9.39,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"Eggplant","hex":"#614051","family":"pink","bestTextColor":"#FFFFFF","contrastBlack":2.36,"contrastWhite":8.9,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#664751","hex":"#664751","family":"pink","bestTextColor":"#FFFFFF","contrastBlack":2.59,"contrastWhite":8.12,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#794034","hex":"#794034","family":"red","bestTextColor":"#FFFFFF","contrastBlack":2.6,"contrastWhite":8.09,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]}]
AI context
{"semanticGroups":["warm red","muted","muted red","Umber adjacent"],"useCases":["color conversion","WCAG contrast checks","CSS color tokens","muted interface themes","high-attention visual states"],"contrastSafeWith":["#FFFFFF","#F5F5F5"],"relatedEndpoints":["https://www.colorsencyclopedia.com/api/hex/664c47.json","https://www.colorsencyclopedia.com/api/hex.json","https://www.colorsencyclopedia.com/api/colors/umber.json","https://www.colorsencyclopedia.com/api/colors/loam.json","https://www.colorsencyclopedia.com/api/colors/eggplant.json"]}
Harmonies
{"complementary":"#476166","analogous":["#664751","#665C47"],"triadic":["#47664C","#4C4766"],"tetradic":["#516647","#476166","#5C4766"],"splitComplementary":["#47665C","#475166"],"monochromatic":["#9B766F","#664C47","#302421"]}
Variants
{"light":"#9B766F","dark":"#302421","saturated":"#794034","desaturated":"#575757","pastel":"#9A9493","neon":"#D62400"}
Nearest named colors
[{"slug":"umber","name":"Umber","hex":"#635147","distance":5.830951894845301},{"slug":"loam","name":"Loam","hex":"#6B4F3A","distance":14.247806848775006},{"slug":"eggplant","name":"Eggplant","hex":"#614051","distance":16.401219466856727},{"slug":"coffee","name":"Coffee","hex":"#6F4E37","distance":18.466185312619388},{"slug":"walnut","name":"Walnut","hex":"#5C4033","distance":25.37715508089904}]
Dataset manifest Version 1.0.0 Build hash published in manifest Canonical page

HEX meaning and use

About #664C47

#664C47 is classified as a warm red value with muted visual character. #664C47 is visually closest to Umber, a named orange color with HEX #635147.

The RGB channels are 102, 76, and 71, with red carrying the strongest channel weight. In HSL, the hue is 10deg with 18% saturation and 34% lightness, so this page treats it as a low-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 muted interface themes. Its luminance is 0.0845, white text provides the stronger contrast for readable interface or documentation use, and Its nearest named-color distance is 5.83, which helps separate this atlas value from adjacent named color records.

WCAG Accessibility

Black text2.69:1AA Fail
White text7.81:1AA Pass

AA text options: #FFFFFF, #F5F5F5.

AAA text options: #FFFFFF, #F5F5F5.

Accessibility-Safe Pairings and Alternatives

Use these pairings when #664C47 needs readable text, badges, interface states, or nearby accessible alternatives.

Black text#0000002.69:1 · Fail
White text#FFFFFF7.81:1 · AAA

Accessible Alternatives

#302421#FFFFFF text · best 15:1#302421
Walnut#FFFFFF text · best 9.39:1#5C4033
Eggplant#FFFFFF text · best 8.9:1#614051
#664751#FFFFFF text · best 8.12:1#664751
#794034#FFFFFF text · best 8.09:1#794034

Generated Palette

#664C47#664C47
#476166#476166
#664751#664751
#665C47#665C47
#9B766F#9B766F
#302421#302421

Color Harmonies

#476166#476166
#664751#664751
#665C47#665C47
#47664C#47664C
#4C4766#4C4766

Variants

#9B766F#9B766F
#302421#302421
#794034#794034
#575757#575757
#9A9493#9A9493
#D62400#D62400

Nearest Named Colors

Umber#635147
Loam#6B4F3A
Eggplant#614051
Coffee#6F4E37
Walnut#5C4033

Related HEX Guides

Umber colorOpen the nearest named color reference for #635147.Loam colorOpen the nearest named color reference for #6B4F3A.Eggplant colorOpen the nearest named color reference for #614051.Red color familyBrowse named red colors related to this HEX value.Warm colorsExplore colors with similar temperature behavior.Muted colorsFind colors in the muted 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.#664C47 APIOpen the machine-readable JSON record for this HEX value.