Blue
blue · #0000FF
HEX
#0000FF
RGB
rgb(0, 0, 255)
CMYK
cmyk(100%, 100%, 0%, 0%)
HSL
hsl(240, 100%, 50%)
LAB
lab(32.3, 79.2, -107.9)
What is Blue?
Blue is the blue reference in the CSS Named Colors. Its sRGB value is #0000FF (rgb 0, 0, 255). It sits in the blue family. The 147 named colors defined by the W3C CSS Color Module Level 4 specification — usable directly in CSS as keywords like 'crimson' or 'rebeccapurple'. See disclaimer for accuracy and trademark notes.
Accessibility
WCAG 2.1 contrast checks for Blue as a background.
Black text on this color
White text on this color
Shades, tints & tonal scale of Blue
An 11-step tonal scale derived from Blue (#0000FF). Click any swatch to copy its HEX. Use these as a starting point for design tokens, hover states, and disabled states in a design system.
50
#EBEBFF
#EBEBFF
100
#D6D6FF
#D6D6FF
200
#ADADFF
#ADADFF
300
#8080FF
#8080FF
400
#4040FF
#4040FF
500
#0000FF
#0000FF
600
#0000D9
#0000D9
700
#0000A6
#0000A6
800
#000073
#000073
900
#000040
#000040
950
#00001F
#00001F
Lighter tints (mixed with white)
15%
#6C6CFF
30%
#9595FF
45%
#B3B3FF
60%
#CBCBFF
75%
#E1E1FF
Darker shades (mixed with black)
15%
#0000ED
30%
#0000DA
45%
#0000C4
60%
#0000AA
75%
#000089
Color harmonies for Blue
Classic color-theory harmonies derived from rotating the hue of Blue. Use these to build accent palettes, brand systems, and accessible UI color pairings.
Complementary
180° opposite — strongest contrast
#0000FF
#0000FF
#FFFF00
#FFFF00
Triadic
Three colors 120° apart
#0000FF
#0000FF
#FF0000
#FF0000
#00FF00
#00FF00
Analogous
Two neighbors ±30° on the wheel
#007FFF
#007FFF
#0000FF
#0000FF
#7F00FF
#7F00FF
Split-complementary
Base + two colors flanking its complement
#0000FF
#0000FF
#FF8000
#FF8000
#80FF00
#80FF00
Tetradic
Two complementary pairs
#0000FF
#0000FF
#FF00FF
#FF00FF
#FFFF00
#FFFF00
#00FF00
#00FF00
Square
Four colors evenly spaced 90° apart
#0000FF
#0000FF
#FF0080
#FF0080
#FFFF00
#FFFF00
#00FF80
#00FF80
Blue in every color space
Full conversion of Blue across the color spaces designers and developers actually use — including OKLCH (the perceptually-uniform space that powers Tailwind v4 and CSS Color Module Level 4) and HWB.
HEX
#0000FF
RGB
rgb(0, 0, 255)
CMYK
cmyk(100%, 100%, 0%, 0%)
HSL
hsl(240, 100%, 50%)
HSV
hsv(240, 100%, 100%)
HWB
hwb(240 0% 0%)
CIE Lab
lab(32.3 79.2 -107.9)
OKLCH
oklch(45.2% 0.313 264.1)
XYZ (D65)
xyz(18.04, 7.22, 95.03)
Copy-ready code for Blue
Drop-in snippets for CSS, Tailwind, Sass, iOS Swift, and Android XML. Click the copy button on any snippet to put it on your clipboard.
CSS
color: #0000FF;
background-color: #0000FF;CSS variable
:root {
--color-blue: #0000FF;
}Tailwind config
// tailwind.config.js
colors: {
'blue': '#0000FF',
}Sass
$color-blue: #0000FF;Swift UIColor
UIColor(red: 0.000, green: 0.000, blue: 1.000, alpha: 1.0)Android XML
<color name="blue">#0000FF</color>Closest match in every color system
The nearest Blue equivalent in every other color system on this site, ranked by ΔE2000 perceptual distance. Useful when translating between design-system, web-standard, and industrial color references.
Closest in CSS Named Colors
Top 6 ΔE2000-closest entries within the same collection.
Closest Pantone matches
Top 6 ΔE2000-closest Pantone references. Cross-system matching is approximate — see disclaimer.
Closest RAL Classic matches
Top 6 ΔE2000-closest RAL Classic references for industrial coating cross-reference.
RAL 5000
#354D73
Violet blue
RAL 5019
#1B5583
Capri blue
RAL 5017
#063971
Traffic blue
RAL 5007
#3E5F8A
Brilliant blue
RAL 5020
#1D334A
Ocean blue
RAL 5023
#49678D
Distant blue
FAQ about Blue
What is the HEX code for Blue?
Blue (blue) has the HEX code #0000FF. In RGB it is rgb(0, 0, 255), and in CMYK it is cmyk(100%, 100%, 0%, 0%).
What is the OKLCH value of Blue?
Blue converts to oklch(0.452 0.313 264.1). OKLCH is the perceptually uniform color space used by Tailwind v4 and CSS Color Module Level 4.
Is Blue accessible for body text?
Used as a background, Blue has a contrast ratio of 2.44:1 with black text and 8.59:1 with white text. WCAG 2.1 AA requires 4.5:1 for normal text. The current recommendation is to use white text and verify in real UI context.
What is the closest Pantone to Blue?
The closest Pantone reference to Blue by ΔE2000 perceptual distance is Pantone Blue 072 C (#10069F). Cross-system Pantone matching is approximate; for color-critical print work, verify with a physical Pantone guide.
What is the closest RAL color to Blue?
The closest RAL Classic reference to Blue by ΔE2000 distance is RAL 5000 (Violet blue, #354D73). RAL is a German industrial coating standard commonly used for paint, powder coat, and architectural specification.
What is the complementary color of Blue?
The complementary color (180° opposite on the HSL color wheel) of Blue is #FFFF00. Use it for high-contrast accents, error states, or call-to-action pairings.
Data provenance & source
CSS Named Colors (CSS Color Module Level 4)
The 147 named colors defined by the W3C CSS Color Module Level 4 specification. Origin: VGA (16) + X11 (rest) + 'rebeccapurple'. Use as a reference for web color names that all browsers natively support. Names like 'crimson' or 'rebeccapurple' work as CSS values without any framework.
- Source type
- derived
- Confidence
- high
- License
- W3C permissive document license
- Last reviewed
- 2026-05-24
Workflow tags
CSS named colors are sRGB digital values defined for browsers. For print, convert to a process-appropriate color and proof against substrate.