Colors Encyclopedia

HEX atlas value

#003399

#003399 is a cool blue HEX color close to Smalt. According to Colors Encyclopedia, it converts to RGB 0, 51, 153, HSL 220, 100%, 30%, has luminance 0.0467, and belongs to the jewel tone group.

bluecooljewel-tone
#003399 Sample readable text
HEX #003399
RGB rgb(0, 51, 153)
HSL hsl(220 100% 30%)
CMYK cmyk(100, 67, 0, 40)
Luminance 0.0467
Contrast Black 1.93:1White 10.86:1

CSS

--color-003399: #003399;
.background-003399 { background-color: #003399; }
.text-003399 { color: #003399; }

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
Luminance0.0467
Black text1.93:1AA Fail
White text10.86:1AA 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":"#003399","rgb":[0,51,153],"hsl":[220,100,30],"cmyk":[100,67,0,40],"luminance":0.0467,"contrast":{"black":1.93,"white":10.86}}
WCAG
{"AA":["#FFFFFF","#F5F5F5"],"AAA":["#FFFFFF","#F5F5F5"]}
Safe pairings
[{"name":"Black text","hex":"#000000","contrast":1.93,"wcagAA":false,"wcagAAA":false},{"name":"White text","hex":"#FFFFFF","contrast":10.86,"wcagAA":true,"wcagAAA":true}]
Accessible alternatives
[{"name":"#00143D","hex":"#00143D","family":"blue","bestTextColor":"#FFFFFF","contrastBlack":1.17,"contrastWhite":17.98,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#190099","hex":"#190099","family":"blue","bestTextColor":"#FFFFFF","contrastBlack":1.5,"contrastWhite":13.98,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"Zaffre","hex":"#0014A8","family":"blue","bestTextColor":"#FFFFFF","contrastBlack":1.67,"contrastWhite":12.61,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"#113988","hex":"#113988","family":"blue","bestTextColor":"#FFFFFF","contrastBlack":1.96,"contrastWhite":10.69,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]},{"name":"Egyptian Blue","hex":"#1034A6","family":"blue","bestTextColor":"#FFFFFF","contrastBlack":2.06,"contrastWhite":10.17,"wcagAA":["#FFFFFF","#F5F5F5"],"wcagAAA":["#FFFFFF","#F5F5F5"]}]
AI context
{"semanticGroups":["cool blue","jewel tone","jewel tone blue","Smalt adjacent"],"useCases":["color conversion","WCAG contrast checks","CSS color tokens","rich accent palettes","calm digital interfaces"],"contrastSafeWith":["#FFFFFF","#F5F5F5"],"relatedEndpoints":["https://www.colorsencyclopedia.com/api/hex/003399.json","https://www.colorsencyclopedia.com/api/hex.json","https://www.colorsencyclopedia.com/api/colors/smalt.json","https://www.colorsencyclopedia.com/api/colors/egyptian-blue.json","https://www.colorsencyclopedia.com/api/colors/cobalt-blue.json"]}
Harmonies
{"complementary":"#996600","analogous":["#007F99","#190099"],"triadic":["#990033","#339900"],"tetradic":["#99007F","#996600","#00991A"],"splitComplementary":["#991900","#7F9900"],"monochromatic":["#0052F5","#003399","#00143D"]}
Variants
{"light":"#0052F5","dark":"#00143D","saturated":"#003399","desaturated":"#113988","pastel":"#2B6CEE","neon":"#0041C2"}
Nearest named colors
[{"slug":"smalt","name":"Smalt","hex":"#003399","distance":0},{"slug":"egyptian-blue","name":"Egyptian Blue","hex":"#1034A6","distance":20.639767440550294},{"slug":"cobalt-blue","name":"Cobalt Blue","hex":"#0047AB","distance":26.90724809414742},{"slug":"zaffre","name":"Zaffre","hex":"#0014A8","distance":34.438350715445125},{"slug":"persian-blue","name":"Persian Blue","hex":"#1C39BB","distance":44.45222154178574}]
Dataset manifest Version 1.0.0 Build hash published in manifest Canonical page

HEX meaning and use

About #003399

#003399 is classified as a cool blue value with jewel tone visual character. #003399 is visually closest to Smalt, a named blue color with HEX #003399.

The RGB channels are 0, 51, and 153, with blue carrying the strongest channel weight. In HSL, the hue is 220deg with 100% saturation and 30% lightness, so this page treats it as a high-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 rich accent palettes. Its luminance is 0.0467, 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 text1.93:1AA Fail
White text10.86:1AA Pass

AA text options: #FFFFFF, #F5F5F5.

AAA text options: #FFFFFF, #F5F5F5.

Accessibility-Safe Pairings and Alternatives

Use these pairings when #003399 needs readable text, badges, interface states, or nearby accessible alternatives.

Black text#0000001.93:1 · Fail
White text#FFFFFF10.86:1 · AAA

Accessible Alternatives

#00143D#FFFFFF text · best 17.98:1#00143D
#190099#FFFFFF text · best 13.98:1#190099
Zaffre#FFFFFF text · best 12.61:1#0014A8
#113988#FFFFFF text · best 10.69:1#113988
Egyptian Blue#FFFFFF text · best 10.17:1#1034A6

Generated Palette

Smalt#003399
#996600#996600
#007F99#007F99
#190099#190099
#0052F5#0052F5
#00143D#00143D

Color Harmonies

#996600#996600
#007F99#007F99
#190099#190099
#990033#990033
#339900#339900

Variants

#0052F5#0052F5
#00143D#00143D
Smalt#003399
#113988#113988
#2B6CEE#2B6CEE
#0041C2#0041C2

Nearest Named Colors

Smalt#003399
Egyptian Blue#1034A6
Cobalt Blue#0047AB
Zaffre#0014A8
Persian Blue#1C39BB

Related HEX Guides

Smalt colorOpen the nearest named color reference for #003399.Egyptian Blue colorOpen the nearest named color reference for #1034A6.Cobalt Blue colorOpen the nearest named color reference for #0047AB.Blue color familyBrowse named blue colors related to this HEX value.Cool colorsExplore colors with similar temperature behavior.Jewel Tone colorsFind colors in the jewel 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.#003399 APIOpen the machine-readable JSON record for this HEX value.