HEX atlas value

#003F5C

#003F5C is a cool blue HEX color nearest Ink Blue. RGB 0, 63, 92, HSL 199° 100% 18%, luminance 0.0433; view contrast and conversions.

blue cool dark jewel-tone

#003F5C Sample readable text

HEX #003F5C

RGB rgb(0, 63, 92)

HSL hsl(199 100% 18%)

CMYK cmyk(100, 32, 0, 64)

Luminance 0.0433

Contrast Black 1.87:1White 11.25:1

CSS

--color-003f5c: #003F5C;
.background-003f5c { background-color: #003F5C; }
.text-003f5c { color: #003F5C; }

HEX meaning and use

About #003F5C

#003F5C is classified as a cool blue value with dark and jewel tone visual character. #003F5C is visually closest to Ink Blue, a named blue color with HEX #003F5C.

The RGB channels are 0, 63, and 92, with blue carrying the strongest channel weight. In HSL, the hue is 199deg with 100% saturation and 18% lightness, so this page treats it as a high-saturation, dark atlas color rather than a generic swatch.

Practical uses for this HEX value include color conversion, WCAG contrast checks, CSS color tokens, and rich accent palettes. Its luminance is 0.0433, white 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 text1.87:1AA Fail

White text11.25:1AA Pass

AA text options: #FFFFFF, #F5F5F5.

AAA text options: #FFFFFF, #F5F5F5.

Accessibility-Safe Pairings and Alternatives

Use these pairings when #003F5C needs readable text, badges, interface states, or nearby accessible alternatives.

Black text#0000001.87:1 · Fail

White text#FFFFFF11.25:1 · AAA

Accessible Alternatives

Black#000000 · #FFFFFF text · best 21:1 #00115C#00115C · #FFFFFF text · best 17.02:1 Sapphire Deep#082567 · #FFFFFF text · best 14.29:1 Prussian Blue#003153 · #FFFFFF text · best 13.43:1 #5C1D00#5C1D00 · #FFFFFF text · best 12.88:1

Generated Palette

Ink Blue#003F5C

#5C1D00#5C1D00

#005C4B#005C4B

#00115C#00115C

#007DB8#007DB8

Black#000000

Color Harmonies

#5C1D00#5C1D00

#005C4B#005C4B

#00115C#00115C

#5C003F#5C003F

#3F5C00#3F5C00

Variants

#007DB8#007DB8

Black#000000

Ink Blue#003F5C

#0A3B52#0A3B52

#1090CB#1090CB

#005B85#005B85

Nearest Named Colors

Ink Blue#003F5C

Prussian Blue#003153

Sapphire Deep#082567

Peacock Blue#005F69

Petrol Blue#005F6A

Luminance0.0433

Black text1.87:1AA Fail

White text11.25:1AA 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":"#003F5C","rgb":[0,63,92],"hsl":[199,100,18],"cmyk":[100,32,0,64],"luminance":0.0433,"contrast":{"black":1.87,"white":11.25}}

WCAG

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

Safe pairings

[{"name":"Black text","hex":"#000000","contrast":1.87,"wcagAA":false,"wcagAAA":false},{"name":"White text","hex":"#FFFFFF","contrast":11.25,"wcagAA":true,"wcagAAA":true}]

Accessible alternatives

[{"name":"Black","hex":"#000000","family":"gray","bestTextColor":"#FFFFFF","contrastBlack":1,"contrastWhite":21,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#00115C","hex":"#00115C","family":"blue","bestTextColor":"#FFFFFF","contrastBlack":1.23,"contrastWhite":17.02,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"Sapphire Deep","hex":"#082567","family":"blue","bestTextColor":"#FFFFFF","contrastBlack":1.47,"contrastWhite":14.29,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"Prussian Blue","hex":"#003153","family":"blue","bestTextColor":"#FFFFFF","contrastBlack":1.56,"contrastWhite":13.43,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#5C1D00","hex":"#5C1D00","family":"orange","bestTextColor":"#FFFFFF","contrastBlack":1.63,"contrastWhite":12.88,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]}]

AI context

{"semanticGroups":["cool blue","dark","jewel tone","dark blue","jewel tone blue","Ink Blue adjacent"],"useCases":["color conversion","WCAG contrast checks","CSS color tokens","rich accent palettes","dark theme accents","calm digital interfaces"],"contrastSafeWith":["#FFFFFF","#F5F5F5"],"relatedEndpoints":["https://www.colorsencyclopedia.com/api/hex/003f5c.json","https://www.colorsencyclopedia.com/api/hex.json","https://www.colorsencyclopedia.com/api/colors/ink-blue.json","https://www.colorsencyclopedia.com/api/colors/prussian-blue.json","https://www.colorsencyclopedia.com/api/colors/sapphire-deep.json"]}

Harmonies

{"complementary":"#5C1D00","analogous":["#005C4B","#00115C"],"triadic":["#5C003F","#3F5C00"],"tetradic":["#4B005C","#5C1D00","#115C00"],"splitComplementary":["#5C0011","#5C4B00"],"monochromatic":["#007DB8","#003F5C","#000000"]}

Variants

{"light":"#007DB8","dark":"#000000","saturated":"#003F5C","desaturated":"#0A3B52","pastel":"#1090CB","neon":"#005B85"}

Nearest named colors

[{"slug":"ink-blue","name":"Ink Blue","hex":"#003F5C","distance":0},{"slug":"prussian-blue","name":"Prussian Blue","hex":"#003153","distance":16.64331697709324},{"slug":"sapphire-deep","name":"Sapphire Deep","hex":"#082567","distance":29.34280150224242},{"slug":"peacock-blue","name":"Peacock Blue","hex":"#005F69","distance":34.539832078341085},{"slug":"petrol-blue","name":"Petrol Blue","hex":"#005F6A","distance":34.92849839314596}]

#003F5C

CSS

About #003F5C

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