HEX atlas value

#FFEF00

#FFEF00 is a warm yellow HEX color nearest Canary Yellow. RGB 255, 239, 0, HSL 56° 100% 50%, luminance 0.8299; view contrast and conversions.

yellow warm vibrant

#FFEF00 Sample readable text

HEX #FFEF00

RGB rgb(255, 239, 0)

HSL hsl(56 100% 50%)

CMYK cmyk(0, 6, 100, 0)

Luminance 0.8299

Contrast Black 17.6:1White 1.19:1

CSS

--color-ffef00: #FFEF00;
.background-ffef00 { background-color: #FFEF00; }
.text-ffef00 { color: #FFEF00; }

HEX meaning and use

About #FFEF00

#FFEF00 is classified as a warm yellow value with vibrant visual character. #FFEF00 is visually closest to Canary Yellow, a named yellow color with HEX #FFEF00.

The RGB channels are 255, 239, and 0, with red carrying the strongest channel weight. In HSL, the hue is 56deg with 100% saturation and 50% lightness, so this page treats it as a high-saturation, mid-lightness atlas color rather than a generic swatch.

Practical uses for this HEX value include color conversion, WCAG contrast checks, CSS color tokens, and high-energy accents. Its luminance is 0.8299, 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 text17.6:1AA Pass

White text1.19:1AA Fail

AA text options: #000000, #1A1A1A, #36454F.

AAA text options: #000000, #1A1A1A, #36454F.

Accessibility-Safe Pairings and Alternatives

Use these pairings when #FFEF00 needs readable text, badges, interface states, or nearby accessible alternatives.

Black text#00000017.6:1 · AAA

White text#FFFFFF1.19:1 · Fail

Accessible Alternatives

Yellow#FFFF00 · #000000 text · best 19.56:1 Lemon#FFF700 · #000000 text · best 18.56:1 Cadmium Yellow#FFF600 · #000000 text · best 18.43:1 #FFF45C#FFF45C · #000000 text · best 18.35:1 #FFEE00#FFEE00 · #000000 text · best 17.48:1

Generated Palette

Canary Yellow#FFEF00

#0011FF#0011FF

#FF6E00#FF6E00

#91FF00#91FF00

#FFF45C#FFF45C

#A39800#A39800

Color Harmonies

#0011FF#0011FF

#FF6E00#FF6E00

#91FF00#91FF00

#00FFEE#00FFEE

#EE00FF#EE00FF

Variants

#FFF45C#FFF45C

#A39800#A39800

#FFEE00#FFEE00

#E3D61C#E3D61C

#F5EE89#F5EE89

#FFF129#FFF129

Nearest Named Colors

Canary Yellow#FFEF00

Cadmium Yellow#FFF600

Lemon#FFF700

Golden Yellow#FFDF00

Yellow#FFFF00

Luminance0.8299

Black text17.6:1AA Pass

White text1.19:1AA 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

Structured sections

Color systems

{"hex":"#FFEF00","rgb":[255,239,0],"hsl":[56,100,50],"cmyk":[0,6,100,0],"luminance":0.8299,"contrast":{"black":17.6,"white":1.19}}

WCAG

{"AA":["#000000","#1A1A1A","#36454F"],"AAA":["#000000","#1A1A1A","#36454F"]}

Safe pairings

[{"name":"Black text","hex":"#000000","contrast":17.6,"wcagAA":true,"wcagAAA":true},{"name":"White text","hex":"#FFFFFF","contrast":1.19,"wcagAA":false,"wcagAAA":false}]

Accessible alternatives

[{"name":"Yellow","hex":"#FFFF00","family":"yellow","bestTextColor":"#000000","contrastBlack":19.56,"contrastWhite":1.07,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A","#36454F"]},{"name":"Lemon","hex":"#FFF700","family":"yellow","bestTextColor":"#000000","contrastBlack":18.56,"contrastWhite":1.13,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A","#36454F"]},{"name":"Cadmium Yellow","hex":"#FFF600","family":"yellow","bestTextColor":"#000000","contrastBlack":18.43,"contrastWhite":1.14,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A","#36454F"]},{"name":"#FFF45C","hex":"#FFF45C","family":"yellow","bestTextColor":"#000000","contrastBlack":18.35,"contrastWhite":1.14,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A","#36454F"]},{"name":"#FFEE00","hex":"#FFEE00","family":"yellow","bestTextColor":"#000000","contrastBlack":17.48,"contrastWhite":1.2,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A","#36454F"]}]

AI context

{"semanticGroups":["warm yellow","vibrant","vibrant yellow","Canary Yellow adjacent"],"useCases":["color conversion","WCAG contrast checks","CSS color tokens","high-energy accents","highlight and warning systems"],"contrastSafeWith":["#000000","#1A1A1A","#36454F"],"relatedEndpoints":["https://www.colorsencyclopedia.com/api/hex/ffef00.json","https://www.colorsencyclopedia.com/api/hex.json","https://www.colorsencyclopedia.com/api/colors/canary-yellow.json","https://www.colorsencyclopedia.com/api/colors/cadmium-yellow.json","https://www.colorsencyclopedia.com/api/colors/lemon.json"]}

Harmonies

{"complementary":"#0011FF","analogous":["#FF6E00","#91FF00"],"triadic":["#00FFEE","#EE00FF"],"tetradic":["#00FF6F","#0011FF","#FF0091"],"splitComplementary":["#0091FF","#6E00FF"],"monochromatic":["#FFF45C","#FFEF00","#A39800"]}

Variants

{"light":"#FFF45C","dark":"#A39800","saturated":"#FFEE00","desaturated":"#E3D61C","pastel":"#F5EE89","neon":"#FFF129"}

Nearest named colors

[{"slug":"canary-yellow","name":"Canary Yellow","hex":"#FFEF00","distance":0},{"slug":"cadmium-yellow","name":"Cadmium Yellow","hex":"#FFF600","distance":7},{"slug":"lemon","name":"Lemon","hex":"#FFF700","distance":8},{"slug":"golden-yellow","name":"Golden Yellow","hex":"#FFDF00","distance":16},{"slug":"yellow","name":"Yellow","hex":"#FFFF00","distance":16}]

#FFEF00

CSS

About #FFEF00

WCAG Accessibility

Accessibility-Safe Pairings and Alternatives

Accessible Alternatives

Generated Palette

Color Harmonies

Variants

Nearest Named Colors

Machine-Readable HEX Data (JSON)

Related HEX Guides