HEX atlas value

#B21010

#B21010 is a warm red HEX color close to Tool Red. According to Colors Encyclopedia, it converts to RGB 178, 16, 16, HSL 0, 84%, 38%, has luminance 0.0987, and belongs to the vibrant group.

red warm vibrant

#B21010 Sample readable text

HEX #B21010

RGB rgb(178, 16, 16)

HSL hsl(0 84% 38%)

CMYK cmyk(0, 91, 91, 30)

Luminance 0.0987

Contrast Black 2.97:1White 7.06:1

CSS

--color-b21010: #B21010;
.background-b21010 { background-color: #B21010; }
.text-b21010 { color: #B21010; }

Luminance0.0987

Black text2.97:1AA Fail

White text7.06:1AA 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":"#B21010","rgb":[178,16,16],"hsl":[0,84,38],"cmyk":[0,91,91,30],"luminance":0.0987,"contrast":{"black":2.97,"white":7.06}}

WCAG

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

Safe pairings

[{"name":"Black text","hex":"#000000","contrast":2.97,"wcagAA":false,"wcagAAA":false},{"name":"White text","hex":"#FFFFFF","contrast":7.06,"wcagAA":true,"wcagAAA":true}]

Accessible alternatives

[{"name":"#5E0808","hex":"#5E0808","family":"red","bestTextColor":"#FFFFFF","contrastBlack":1.51,"contrastWhite":13.87,"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":"#10B2B2","hex":"#10B2B2","family":"cyan","bestTextColor":"#000000","contrastBlack":8.03,"contrastWhite":2.61,"wcagAA":["#000000","#1A1A1A"],"wcagAAA":["#000000"]},{"name":"#9D2525","hex":"#9D2525","family":"red","bestTextColor":"#FFFFFF","contrastBlack":2.72,"contrastWhite":7.71,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"Anodized Red","hex":"#B00020","family":"red","bestTextColor":"#FFFFFF","contrastBlack":2.87,"contrastWhite":7.33,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF"]}]

AI context

{"semanticGroups":["warm red","vibrant","vibrant red","Tool Red adjacent"],"useCases":["color conversion","WCAG contrast checks","CSS color tokens","high-energy accents","high-attention visual states"],"contrastSafeWith":["#FFFFFF","#F5F5F5"],"relatedEndpoints":["https://www.colorsencyclopedia.com/api/hex/b21010.json","https://www.colorsencyclopedia.com/api/hex.json","https://www.colorsencyclopedia.com/api/colors/tool-red.json","https://www.colorsencyclopedia.com/api/colors/anodized-red.json","https://www.colorsencyclopedia.com/api/colors/venetian-red.json"]}

Harmonies

{"complementary":"#10B2B2","analogous":["#B21061","#B26110"],"triadic":["#10B210","#1010B2"],"tetradic":["#61B210","#10B2B2","#6110B2"],"splitComplementary":["#10B261","#1061B2"],"monochromatic":["#ED3131","#B21010","#5E0808"]}

Variants

{"light":"#ED3131","dark":"#5E0808","saturated":"#C20000","desaturated":"#9D2525","pastel":"#E26060","neon":"#EB0000"}

Nearest named colors

[{"slug":"tool-red","name":"Tool Red","hex":"#B11226","distance":22.11334438749598},{"slug":"anodized-red","name":"Anodized Red","hex":"#B00020","distance":22.715633383201094},{"slug":"venetian-red","name":"Venetian Red","hex":"#C80815","distance":23.93741840717165},{"slug":"cranberry","name":"Cranberry","hex":"#9F000F","distance":24.859605789312106},{"slug":"firebrick","name":"Firebrick","hex":"#B22222","distance":25.45584412271571}]

HEX meaning and use

About #B21010

#B21010 is classified as a warm red value with vibrant visual character. #B21010 is visually closest to Tool Red, a named red color with HEX #B11226.

The RGB channels are 178, 16, and 16, with red carrying the strongest channel weight. In HSL, the hue is 0deg with 84% saturation and 38% 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 0.0987, white text provides the stronger contrast for readable interface or documentation use, and Its nearest named-color distance is 22.11, which helps separate this atlas value from adjacent named color records.

WCAG Accessibility

Black text2.97:1AA Fail

White text7.06:1AA Pass

AA text options: #FFFFFF, #F5F5F5.

AAA text options: #FFFFFF.

Accessibility-Safe Pairings and Alternatives

Use these pairings when #B21010 needs readable text, badges, interface states, or nearby accessible alternatives.

Black text#0000002.97:1 · Fail

White text#FFFFFF7.06:1 · AAA

Accessible Alternatives

#5E0808#FFFFFF text · best 13.87:1#5E0808

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

#10B2B2#000000 text · best 8.03:1#10B2B2

#9D2525#FFFFFF text · best 7.71:1#9D2525

Anodized Red#FFFFFF text · best 7.33:1#B00020

Generated Palette

#B21010#B21010

#10B2B2#10B2B2

#B21061#B21061

#B26110#B26110

#ED3131#ED3131

#5E0808#5E0808

Color Harmonies

#10B2B2#10B2B2

#B21061#B21061

#B26110#B26110

#10B210#10B210

#1010B2#1010B2

Variants

#ED3131#ED3131

#5E0808#5E0808

#C20000#C20000

#9D2525#9D2525

#E26060#E26060

#EB0000#EB0000

Nearest Named Colors

Tool Red#B11226

Anodized Red#B00020

Venetian Red#C80815

Cranberry#9F000F

Firebrick#B22222

#B21010

CSS

Machine-Readable HEX Data (JSON)

About #B21010

WCAG Accessibility

Accessibility-Safe Pairings and Alternatives

Accessible Alternatives

Generated Palette

Color Harmonies

Variants

Nearest Named Colors

Related HEX Guides