Colors Encyclopedia

HEX atlas value

#66631E

#66631E is a warm yellow HEX color close to Fern Frond. According to Colors Encyclopedia, it converts to RGB 102, 99, 30, HSL 58, 55%, 26%, has luminance 0.1184, and belongs to the earth tone group.

yellowwarmearth-tone
#66631E Sample readable text
HEX #66631E
RGB rgb(102, 99, 30)
HSL hsl(58 55% 26%)
CMYK cmyk(0, 3, 71, 60)
Luminance 0.1184
Contrast Black 3.37:1White 6.24:1

CSS

--color-66631e: #66631E;
.background-66631e { background-color: #66631E; }
.text-66631e { color: #66631E; }

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
Luminance0.1184
Black text3.37:1AA Fail
White text6.24:1AA 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":"#66631E","rgb":[102,99,30],"hsl":[58,55,26],"cmyk":[0,3,71,60],"luminance":0.1184,"contrast":{"black":3.37,"white":6.24}}
WCAG
{"AA":["#FFFFFF","#F5F5F5"],"AAA":[]}
Safe pairings
[{"name":"Black text","hex":"#000000","contrast":3.37,"wcagAA":false,"wcagAAA":false},{"name":"White text","hex":"#FFFFFF","contrast":6.24,"wcagAA":true,"wcagAAA":false}]
Accessible alternatives
[{"name":"#201F09","hex":"#201F09","family":"yellow","bestTextColor":"#FFFFFF","contrastBlack":1.26,"contrastWhite":16.64,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#1E2067","hex":"#1E2067","family":"blue","bestTextColor":"#FFFFFF","contrastBlack":1.46,"contrastWhite":14.4,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#67401E","hex":"#67401E","family":"orange","bestTextColor":"#FFFFFF","contrastBlack":2.33,"contrastWhite":9.02,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#AEAA32","hex":"#AEAA32","family":"yellow","bestTextColor":"#000000","contrastBlack":8.6,"contrastWhite":2.44,"wcagAA":["#000000","#1A1A1A"],"wcagAAA":["#000000","#1A1A1A"]},{"name":"Loam","hex":"#6B4F3A","family":"orange","bestTextColor":"#FFFFFF","contrastBlack":2.8,"contrastWhite":7.49,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF"]}]
AI context
{"semanticGroups":["warm yellow","earth tone","earth tone yellow","Fern Frond adjacent"],"useCases":["color conversion","WCAG contrast checks","CSS color tokens","natural palettes","highlight and warning systems"],"contrastSafeWith":["#FFFFFF","#F5F5F5"],"relatedEndpoints":["https://www.colorsencyclopedia.com/api/hex/66631e.json","https://www.colorsencyclopedia.com/api/hex.json","https://www.colorsencyclopedia.com/api/colors/fern-frond.json","https://www.colorsencyclopedia.com/api/colors/dark-olive-green.json","https://www.colorsencyclopedia.com/api/colors/moss-deep.json"]}
Harmonies
{"complementary":"#1E2067","analogous":["#67401E","#45671E"],"triadic":["#1E6764","#641E67"],"tetradic":["#1E6740","#1E2067","#671E45"],"splitComplementary":["#1E4567","#401E67"],"monochromatic":["#AEAA32","#66631E","#201F09"]}
Variants
{"light":"#AEAA32","dark":"#201F09","saturated":"#75720F","desaturated":"#58572C","pastel":"#B4B150","neon":"#ADA800"}
Nearest named colors
[{"slug":"fern-frond","name":"Fern Frond","hex":"#657220","distance":15.165750888103101},{"slug":"dark-olive-green","name":"Dark Olive Green","hex":"#556B2F","distance":25.337718918639855},{"slug":"moss-deep","name":"Moss Deep","hex":"#4A5D23","distance":29.068883707497267},{"slug":"coffee","name":"Coffee","hex":"#6F4E37","distance":33.8673884437522},{"slug":"loam","name":"Loam","hex":"#6B4F3A","distance":34.77067730142742}]
Dataset manifest Version 1.0.0 Build hash published in manifest Canonical page

HEX meaning and use

About #66631E

#66631E is classified as a warm yellow value with earth tone visual character. #66631E is visually closest to Fern Frond, a named green color with HEX #657220.

The RGB channels are 102, 99, and 30, with red carrying the strongest channel weight. In HSL, the hue is 58deg with 55% saturation and 26% lightness, so this page treats it as a moderate-saturation, dark 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 natural palettes. Its luminance is 0.1184, white text provides the stronger contrast for readable interface or documentation use, and Its nearest named-color distance is 15.17, which helps separate this atlas value from adjacent named color records.

WCAG Accessibility

Black text3.37:1AA Fail
White text6.24:1AA Pass

AA text options: #FFFFFF, #F5F5F5.

AAA text options: none in seed set.

Accessibility-Safe Pairings and Alternatives

Use these pairings when #66631E needs readable text, badges, interface states, or nearby accessible alternatives.

Black text#0000003.37:1 · Fail
White text#FFFFFF6.24:1 · AA

Accessible Alternatives

#201F09#FFFFFF text · best 16.64:1#201F09
#1E2067#FFFFFF text · best 14.4:1#1E2067
#67401E#FFFFFF text · best 9.02:1#67401E
#AEAA32#000000 text · best 8.6:1#AEAA32
Loam#FFFFFF text · best 7.49:1#6B4F3A

Generated Palette

#66631E#66631E
#1E2067#1E2067
#67401E#67401E
#45671E#45671E
#AEAA32#AEAA32
#201F09#201F09

Color Harmonies

#1E2067#1E2067
#67401E#67401E
#45671E#45671E
#1E6764#1E6764
#641E67#641E67

Variants

#AEAA32#AEAA32
#201F09#201F09
#75720F#75720F
#58572C#58572C
#B4B150#B4B150
#ADA800#ADA800

Nearest Named Colors

Fern Frond#657220
Dark Olive Green#556B2F
Moss Deep#4A5D23
Coffee#6F4E37
Loam#6B4F3A

Related HEX Guides

Fern Frond colorOpen the nearest named color reference for #657220.Dark Olive Green colorOpen the nearest named color reference for #556B2F.Moss Deep colorOpen the nearest named color reference for #4A5D23.Yellow color familyBrowse named yellow colors related to this HEX value.Warm colorsExplore colors with similar temperature behavior.Earth Tone colorsFind colors in the earth tone 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.#66631E APIOpen the machine-readable JSON record for this HEX value.