Blue1
blue1 · #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 Blue1?
Blue1 is the blue1 reference in the X11 named colors. Its sRGB value is #0000FF (rgb 0, 0, 255). It sits in the blue family. Historical X Window System color names — the numbered 1-4 lightness variants of the classic xorg-server rgb.txt palette. See disclaimer for accuracy and trademark notes.
Accessibility
WCAG 2.1 contrast checks for Blue1 as a background.
Black text on this color
White text on this color
Shades, tints & tonal scale of Blue1
An 11-step tonal scale derived from Blue1 (#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 Blue1
Classic color-theory harmonies derived from rotating the hue of Blue1. 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
Blue1 in every color space
Full conversion of Blue1 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 Blue1
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-blue1: #0000FF;
}Tailwind config
// tailwind.config.js
colors: {
'blue1': '#0000FF',
}Sass
$color-blue1: #0000FF;Swift UIColor
UIColor(red: 0.000, green: 0.000, blue: 1.000, alpha: 1.0)Android XML
<color name="blue1">#0000FF</color>Closest match in every color system
The nearest Blue1 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 X11 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 Blue1
What is the HEX code for Blue1?
Blue1 (blue1) 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 Blue1?
Blue1 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 Blue1 accessible for body text?
Used as a background, Blue1 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 Blue1?
The closest Pantone reference to Blue1 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 Blue1?
The closest RAL Classic reference to Blue1 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 Blue1?
The complementary color (180° opposite on the HSL color wheel) of Blue1 is #FFFF00. Use it for high-contrast accents, error states, or call-to-action pairings.
Data provenance & source
X11 named colors (xorg rgb.txt)
The historical X11 color name list shipped in the xorg-server rgb.txt file. Roughly 550 entries covering classic computing color names like 'PapayaWhip', 'MediumAquamarine', and 'DarkSlateGray'. Many CSS named colors originate here. Use as a reference for legacy and creative color names. Most modern CSS implementations accept these names directly.
- Source type
- derived
- Confidence
- high
- License
- MIT/X11 license (X Consortium)
- Last reviewed
- 2026-05-24
Workflow tags
X11 colors are sRGB digital values from a 1980s color system. For print, convert to a process-appropriate color and proof against substrate.