Color brief · Blue
#151D40 (#151D40) — practical notes
#151D40 (#151d40) sits in the blue family at about 229° hue, 51% saturation, and 17% lightness. Contrast is 16.38:1 on white and 1.28:1 on black, so white labels read more clearly on the swatch itself. Nearest Tailwind token: blue-950 (approximation unless the hex is an official scale stop).
- body text, chrome, and dark-mode surfaces
- text or icons on a white canvas
On a black or near-black UI, #151d40 is 1.28:1. Prefer it as a fill, border, or large heading rather than 16px copy.
Specs & accessibility references: W3C WCAG 2.1 contrast minimum · MDN CSS color values · CSS Color Module Level 4 · WebAIM contrast guide.
COLOR EXPLORER
THE ORIGINAL SWATCH#151D40
100% opacity · sRGB
YOUR NEXT GREAT ACCENT
#151D40
Explore the codes, find a readable pairing, and see how this color feels in a real design.
HEX
#151D40RGB
rgb(21, 29, 64)HSL
hsl(229, 51%, 17%)PUT IT INTO PRACTICE
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Try it with another color before you commit.
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Selected text: #151D40CONTRAST RATIO16.38:1
- AA · normal text
- Pass
- AA · large text
- Pass
- AAA · normal text
- Pass
Normal text: AA 4.5:1, AAA 7:1. Large text: AA 3:1 (24px regular or about 19px bold).
Against white16.38:1
Against black1.28:1
Results use the exact pair, at full opacity. WCAG contrast guidance ↗
A color worth keeping? Save it above or share it.
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Color codes
HEX
#151d40
RGB
rgb(21, 29, 64)
HSL
hsl(229, 51%, 17%)
OKLCH
oklch(0.245 0.0671 271.02)
CMYK
cmyk(67%, 55%, 0%, 75%)
CSS variable
--color-151d40: #151d40;
CMYK is an approximate reference; print output depends on the color profile. HSV and CMYK are not CSS color functions.
OKLCH
Perceptual 50–950 scale
Generated in OKLCH from this hex. Not an official Tailwind scale unless the hex itself is a Tailwind token.
Palette
Tints & shades
Full scale from light tints through the base color into deep shades
Palette
Tints
Mixed toward white — soft backgrounds and highlights
Palette
Shades
Mixed toward black — depth, text, and emphasis
Palette
Tones
Mixed toward neutral grey — muted UI surfaces
Harmony
Complementary
Opposite on the color wheel for contrast
Harmony
Analogous
Neighbors that sit comfortably together
Harmony
Triadic
Evenly spaced triad for vibrant sets
Harmony
Split complementary
Base plus two accents beside the complement
Harmony
Monochromatic
Same hue, varied lightness and saturation
Export
Developer code
css
:root {
--color151d40-1: #151d40;
}Design systems
Nearest official tokens
An arbitrary HEX is not an official Tailwind, Material, or Bootstrap color. Distance is CIEDE2000.
Nearest Tailwind color
blue-950
Noticeably different · ΔE 4.29 · #172554
Nearest CSS named color
MidnightBlue
Very different · ΔE 10.7 · #191970
Nearest Material color
indigo-900
Very different · ΔE 11.76 · #1A237E
Nearest Bootstrap color
dark
Very different · ΔE 14.72 · #212529
Using this color
Where #151d40 works
#151D40 (#151d40) sits in the blue family at about 229° hue, 51% saturation, and 17% lightness. Contrast is 16.38:1 on white and 1.28:1 on black, so white labels read more clearly on the swatch itself. Nearest Tailwind token: blue-950 (approximation unless the hex is an official scale stop).
Sensible jobs for this swatch
- body text, chrome, and dark-mode surfaces
- text or icons on a white canvas
On a black or near-black UI, #151d40 is 1.28:1. Prefer it as a fill, border, or large heading rather than 16px copy.
Family context: Trust, calm, and professionalism. The most used color in SaaS, finance, and healthcare. Common uses still include buttons, charts, and accents in the Blue range — always verify the pair for this exact hex in the contrast checker.
Related
Similar & related colors
Nearby colors from the library by perceptual distance