HEX atlas value

#21CA37

#21CA37 is a cool green HEX color close to Lime Green. According to Colors Encyclopedia, it converts to RGB 33, 202, 55, HSL 128, 72%, 46%, has luminance 0.4284, and belongs to the vibrant group.

green cool vibrant

#21CA37 Sample readable text

HEX #21CA37

RGB rgb(33, 202, 55)

HSL hsl(128 72% 46%)

CMYK cmyk(84, 0, 73, 21)

Luminance 0.4284

Contrast Black 9.57:1White 2.19:1

CSS

--color-21ca37: #21CA37;
.background-21ca37 { background-color: #21CA37; }
.text-21ca37 { color: #21CA37; }

Luminance0.4284

Black text9.57:1AA Pass

White text2.19:1AA 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":"#21CA37","rgb":[33,202,55],"hsl":[128,72,46],"cmyk":[84,0,73,21],"luminance":0.4284,"contrast":{"black":9.57,"white":2.19}}

WCAG

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

Safe pairings

[{"name":"Black text","hex":"#000000","contrast":9.57,"wcagAA":true,"wcagAAA":true},{"name":"White text","hex":"#FFFFFF","contrast":2.19,"wcagAA":false,"wcagAAA":false}]

Accessible alternatives

[{"name":"Neon Green","hex":"#39FF14","family":"green","bestTextColor":"#000000","contrastBlack":15.49,"contrastWhite":1.36,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A","#36454F"]},{"name":"#61E573","hex":"#61E573","family":"green","bestTextColor":"#000000","contrastBlack":12.96,"contrastWhite":1.62,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A"]},{"name":"#07E424","hex":"#07E424","family":"green","bestTextColor":"#000000","contrastBlack":12.13,"contrastWhite":1.73,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A"]},{"name":"#5FCA21","hex":"#5FCA21","family":"green","bestTextColor":"#000000","contrastBlack":9.96,"contrastWhite":2.11,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A"]},{"name":"Lime Green","hex":"#32CD32","family":"green","bestTextColor":"#000000","contrastBlack":9.91,"contrastWhite":2.12,"wcagAA":["#000000","#1A1A1A","#36454F"],"wcagAAA":["#000000","#1A1A1A"]}]

AI context

{"semanticGroups":["cool green","vibrant","vibrant green","Lime Green adjacent"],"useCases":["color conversion","WCAG contrast checks","CSS color tokens","high-energy accents","botanical and wellness palettes"],"contrastSafeWith":["#000000","#1A1A1A","#36454F"],"relatedEndpoints":["https://www.colorsencyclopedia.com/api/hex/21ca37.json","https://www.colorsencyclopedia.com/api/hex.json","https://www.colorsencyclopedia.com/api/colors/lime-green.json","https://www.colorsencyclopedia.com/api/colors/kelly-green.json","https://www.colorsencyclopedia.com/api/colors/forest-green.json"]}

Harmonies

{"complementary":"#CA21B3","analogous":["#5FCA21","#21CA8C"],"triadic":["#3721CA","#CA3721"],"tetradic":["#215FCA","#CA21B3","#CA8C21"],"splitComplementary":["#8C21CA","#CA215F"],"monochromatic":["#61E573","#21CA37","#147B22"]}

Variants

{"light":"#61E573","dark":"#147B22","saturated":"#07E424","desaturated":"#3BB04A","pastel":"#8BDF96","neon":"#14FF34"}

Nearest named colors

[{"slug":"lime-green","name":"Lime Green","hex":"#32CD32","distance":17.97220075561143},{"slug":"kelly-green","name":"Kelly Green","hex":"#4CBB17","distance":55.65968020030299},{"slug":"forest-green","name":"Forest Green","hex":"#228B22","distance":66.41535966928132},{"slug":"neon-green","name":"Neon Green","hex":"#39FF14","distance":67.89698078707183},{"slug":"medium-sea-green","name":"Medium Sea Green","hex":"#3CB371","distance":67.98529252713413}]

HEX meaning and use

About #21CA37

#21CA37 is classified as a cool green value with vibrant visual character. #21CA37 is visually closest to Lime Green, a named green color with HEX #32CD32.

The RGB channels are 33, 202, and 55, with green carrying the strongest channel weight. In HSL, the hue is 128deg with 72% saturation and 46% 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 0.4284, black text provides the stronger contrast for readable interface or documentation use, and Its nearest named-color distance is 17.97, which helps separate this atlas value from adjacent named color records.

WCAG Accessibility

Black text9.57:1AA Pass

White text2.19:1AA Fail

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

AAA text options: #000000, #1A1A1A.

Accessibility-Safe Pairings and Alternatives

Use these pairings when #21CA37 needs readable text, badges, interface states, or nearby accessible alternatives.

Black text#0000009.57:1 · AAA

White text#FFFFFF2.19:1 · Fail

Accessible Alternatives

Neon Green#000000 text · best 15.49:1#39FF14

#61E573#000000 text · best 12.96:1#61E573

#07E424#000000 text · best 12.13:1#07E424

#5FCA21#000000 text · best 9.96:1#5FCA21

Lime Green#000000 text · best 9.91:1#32CD32

Generated Palette

#21CA37#21CA37

#CA21B3#CA21B3

#5FCA21#5FCA21

#21CA8C#21CA8C

#61E573#61E573

#147B22#147B22

Color Harmonies

#CA21B3#CA21B3

#5FCA21#5FCA21

#21CA8C#21CA8C

#3721CA#3721CA

#CA3721#CA3721

Variants

#61E573#61E573

#147B22#147B22

#07E424#07E424

#3BB04A#3BB04A

#8BDF96#8BDF96

#14FF34#14FF34

Nearest Named Colors

Lime Green#32CD32

Kelly Green#4CBB17

Forest Green#228B22

Neon Green#39FF14

Medium Sea Green#3CB371

#21CA37

CSS

Machine-Readable HEX Data (JSON)

About #21CA37

WCAG Accessibility

Accessibility-Safe Pairings and Alternatives

Accessible Alternatives

Generated Palette

Color Harmonies

Variants

Nearest Named Colors

Related HEX Guides