Blue 9
blue-9 · #1864AB
HEX
#1864AB
RGB
rgb(24, 100, 171)
CMYK
cmyk(86%, 42%, 0%, 33%)
HSL
hsl(209, 75%, 38%)
LAB
lab(41.6, 4.5, -44.2)
What is Blue 9?
Blue 9 is the blue-9 reference in the Open Color. Its sRGB value is #1864AB (rgb 24, 100, 171). 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 9 as a background.
Black text on this color
White text on this color
Shades, tints & tonal scale of Blue 9
An 11-step tonal scale derived from Blue 9 (#1864AB). 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
#EDF3F8
#EDF3F8
100
#DAE6F2
#DAE6F2
200
#B5CDE4
#B5CDE4
300
#8CB2D5
#8CB2D5
400
#528BC0
#528BC0
500
#1864AB
#1864AB
600
#145591
#145591
700
#10416F
#10416F
800
#0B2D4D
#0B2D4D
900
#06192B
#06192B
950
#030C15
#030C15
Lighter tints (mixed with white)
15%
#6F8BBB
30%
#96A8C9
45%
#B4BFD6
60%
#CCD3E2
75%
#E1E5EE
Darker shades (mixed with black)
15%
#165D9F
30%
#135491
45%
#104B82
60%
#0C4070
75%
#08325A
Color harmonies for Blue 9
Classic color-theory harmonies derived from rotating the hue of Blue 9. Use these to build accent palettes, brand systems, and accessible UI color pairings.
Complementary
180° opposite — strongest contrast
#1864AB
#1864AB
#AA5E18
#AA5E18
Triadic
Three colors 120° apart
#1864AB
#1864AB
#AA1863
#AA1863
#63AA18
#63AA18
Analogous
Two neighbors ±30° on the wheel
#18AAA7
#18AAA7
#1864AB
#1864AB
#181BAA
#181BAA
Split-complementary
Base + two colors flanking its complement
#1864AB
#1864AB
#AA181B
#AA181B
#AAA718
#AAA718
Tetradic
Two complementary pairs
#1864AB
#1864AB
#5E18AA
#5E18AA
#AA5E18
#AA5E18
#63AA18
#63AA18
Square
Four colors evenly spaced 90° apart
#1864AB
#1864AB
#A718AA
#A718AA
#AA5E18
#AA5E18
#1BAA18
#1BAA18
Blue 9 in every color space
Full conversion of Blue 9 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
#1864AB
RGB
rgb(24, 100, 171)
CMYK
cmyk(86%, 42%, 0%, 33%)
HSL
hsl(209, 75%, 38%)
HSV
hsv(209, 86%, 67%)
HWB
hwb(209 9% 33%)
CIE Lab
lab(41.6 4.5 -44.2)
OKLCH
oklch(49.7% 0.133 251.6)
XYZ (D65)
xyz(12.28, 12.25, 40.24)
Copy-ready code for Blue 9
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: #1864AB;
background-color: #1864AB;CSS variable
:root {
--color-blue-9: #1864AB;
}Tailwind config
// tailwind.config.js
colors: {
'blue-9': '#1864AB',
}Sass
$color-blue-9: #1864AB;Swift UIColor
UIColor(red: 0.094, green: 0.392, blue: 0.671, alpha: 1.0)Android XML
<color name="blue-9">#1864AB</color>Closest match in every color system
The nearest Blue 9 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 5015
#2271B3
Sky blue
RAL 5007
#3E5F8A
Brilliant blue
RAL 5023
#49678D
Distant blue
RAL 5019
#1B5583
Capri blue
RAL 5000
#354D73
Violet blue
RAL 5012
#3B83BD
Light blue
FAQ about Blue 9
What is the HEX code for Blue 9?
Blue 9 (blue-9) has the HEX code #1864AB. In RGB it is rgb(24, 100, 171), and in CMYK it is cmyk(86%, 42%, 0%, 33%).
What is the OKLCH value of Blue 9?
Blue 9 converts to oklch(0.497 0.133 251.6). OKLCH is the perceptually uniform color space used by Tailwind v4 and CSS Color Module Level 4.
Is Blue 9 accessible for body text?
Used as a background, Blue 9 has a contrast ratio of 3.45:1 with black text and 6.09:1 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 9?
The closest Pantone reference to Blue 9 by ΔE2000 perceptual distance is Pantone 300 C (#005EB8). 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 9?
The closest RAL Classic reference to Blue 9 by ΔE2000 distance is RAL 5015 (Sky blue, #2271B3). RAL is a German industrial coating standard commonly used for paint, powder coat, and architectural specification.
What is the complementary color of Blue 9?
The complementary color (180° opposite on the HSL color wheel) of Blue 9 is #AA5E18. 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.