Blue 0
blue-0 · #E7F5FF
HEX
#E7F5FF
RGB
rgb(231, 245, 255)
CMYK
cmyk(9%, 4%, 0%, 0%)
HSL
hsl(205, 100%, 95%)
LAB
lab(95.8, -2.7, -6.4)
What is Blue 0?
Blue 0 is the blue-0 reference in the Open Color. Its sRGB value is #E7F5FF (rgb 231, 245, 255). It sits in the blue family. Open Color, an open-source color palette by Heeyeun designed for UI work. 13 hues across 10 shades (0 to 9) tuned for screen legibility and accessibility. See disclaimer for accuracy and trademark notes.
Accessibility
WCAG 2.1 contrast checks for Blue 0 as a background.
Black text on this color
White text on this color
Shades, tints & tonal scale of Blue 0
An 11-step tonal scale derived from Blue 0 (#E7F5FF). 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
#FDFEFF
#FDFEFF
100
#FBFDFF
#FBFDFF
200
#F7FCFF
#F7FCFF
300
#F3FAFF
#F3FAFF
400
#EDF8FF
#EDF8FF
500
#E7F5FF
#E7F5FF
600
#C4D0D9
#C4D0D9
700
#969FA6
#969FA6
800
#686E73
#686E73
900
#3A3D40
#3A3D40
950
#1C1D1F
#1C1D1F
Lighter tints (mixed with white)
15%
#EBF7FF
30%
#EFF8FF
45%
#F2FAFF
60%
#F6FBFF
75%
#F9FDFF
Darker shades (mixed with black)
15%
#D7E4ED
30%
#C5D1DA
45%
#B1BCC4
60%
#99A3AA
75%
#7B8389
Color harmonies for Blue 0
Classic color-theory harmonies derived from rotating the hue of Blue 0. Use these to build accent palettes, brand systems, and accessible UI color pairings.
Complementary
180° opposite — strongest contrast
#E7F5FF
#E7F5FF
#FFF0E5
#FFF0E5
Triadic
Three colors 120° apart
#E7F5FF
#E7F5FF
#FFE5F4
#FFE5F4
#F4FFE5
#F4FFE5
Analogous
Two neighbors ±30° on the wheel
#E5FFFD
#E5FFFD
#E7F5FF
#E7F5FF
#E5E8FF
#E5E8FF
Split-complementary
Base + two colors flanking its complement
#E7F5FF
#E7F5FF
#FFE5E8
#FFE5E8
#FFFDE5
#FFFDE5
Tetradic
Two complementary pairs
#E7F5FF
#E7F5FF
#F0E5FF
#F0E5FF
#FFF0E5
#FFF0E5
#F4FFE5
#F4FFE5
Square
Four colors evenly spaced 90° apart
#E7F5FF
#E7F5FF
#FDE5FF
#FDE5FF
#FFF0E5
#FFF0E5
#E8FFE5
#E8FFE5
Blue 0 in every color space
Full conversion of Blue 0 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
#E7F5FF
RGB
rgb(231, 245, 255)
CMYK
cmyk(9%, 4%, 0%, 0%)
HSL
hsl(205, 100%, 95%)
HSV
hsv(205, 9%, 100%)
HWB
hwb(205 91% 0%)
CIE Lab
lab(95.8 -2.7 -6.4)
OKLCH
oklch(96.3% 0.020 238.7)
XYZ (D65)
xyz(83.65, 89.51, 107.46)
Copy-ready code for Blue 0
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: #E7F5FF;
background-color: #E7F5FF;CSS variable
:root {
--color-blue-0: #E7F5FF;
}Tailwind config
// tailwind.config.js
colors: {
'blue-0': '#E7F5FF',
}Sass
$color-blue-0: #E7F5FF;Swift UIColor
UIColor(red: 0.906, green: 0.961, blue: 1.000, alpha: 1.0)Android XML
<color name="blue-0">#E7F5FF</color>Closest match in every color system
The nearest Blue 0 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 Open Color
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 9003
#F4F4F4
Signal white
RAL 9016
#F6F6F6
Traffic white
RAL 9010
#FFFFFF
Pure white
RAL 7035
#D7D7D7
Light grey
RAL 9018
#D7D7D7
Papyrus white
RAL 9002
#E7EBDA
Grey white
FAQ about Blue 0
What is the HEX code for Blue 0?
Blue 0 (blue-0) has the HEX code #E7F5FF. In RGB it is rgb(231, 245, 255), and in CMYK it is cmyk(9%, 4%, 0%, 0%).
What is the OKLCH value of Blue 0?
Blue 0 converts to oklch(0.963 0.020 238.7). OKLCH is the perceptually uniform color space used by Tailwind v4 and CSS Color Module Level 4.
Is Blue 0 accessible for body text?
Used as a background, Blue 0 has a contrast ratio of 18.90:1 with black text and 1.11:1 with white text. WCAG 2.1 AA requires 4.5:1 for normal text. The current recommendation is to use black text and verify in real UI context.
What is the closest Pantone to Blue 0?
The closest Pantone reference to Blue 0 by ΔE2000 perceptual distance is Pantone 290 C (#B9D9EB). 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 0?
The closest RAL Classic reference to Blue 0 by ΔE2000 distance is RAL 9003 (Signal white, #F4F4F4). RAL is a German industrial coating standard commonly used for paint, powder coat, and architectural specification.
What is the complementary color of Blue 0?
The complementary color (180° opposite on the HSL color wheel) of Blue 0 is #FFF0E5. Use it for high-contrast accents, error states, or call-to-action pairings.
Data provenance & source
Open Color (Yeun)
Open Color, an open-source color palette by Heeyeun designed for UI designers and developers. 13 hues across 10 shades. Use as a designer-friendly palette alternative to Tailwind. Values are intentionally chosen for UI legibility and accessibility.
- Source type
- derived
- Confidence
- high
- License
- MIT
- Last reviewed
- 2026-05-24
Workflow tags
Open Color values are tuned for digital UI. For print, treat as a starting point and proof against the substrate.