#283F57

Accessibility

AAA

10.83:1

Vs white / black

10.83:1 · 1.94:1

Sources

Library color

Codes

Formats

HEX

#283f57

RGB

rgb(40, 63, 87)

RGBA

rgba(40, 63, 87, 1)

HSL

hsl(211, 37%, 25%)

HSLA

hsla(211, 37%, 25%, 1)

HSV

hsv(211, 54%, 34%)

LAB

lab(25.84% -1.21 -17.15)

LCH

lch(25.84% 17.19 265.96)

OKLAB

oklab(0.36 -0.0171 -0.0479)

OKLCH

oklch(0.36 0.0509 250.35)

XYZ

xyz(4.37, 4.69, 9.69)

CMYK

cmyk(54%, 28%, 0%, 66%)

CSS

color: #283f57;

CSS variable

--color-283f57: #283f57;

SCSS

$color-283f57: #283f57;

JavaScript

const color = "#283f57";

TypeScript

const color: string = "#283f57";

React

style={{ backgroundColor: "#283f57" }}

JSON

{ "hex": "#283f57", "rgb": { "r": 40, "g": 63, "b": 87 }, "oklch": "oklch(0.36 0.0509 250.35)" }

Export

Developer code

css

:root {
  --#283f57-1: #283f57;
}

Design systems

Nearest official tokens

An arbitrary HEX is not an official Tailwind, Material, or Bootstrap color. Distance is CIEDE2000.

Nearest Tailwind color

slate-700

Noticeably different · ΔE 2.82 · #334155

Nearest CSS named color

DarkSlateBlue

Very different · ΔE 11.02 · #483D8B

Nearest Material color

blue-grey-800

Very different · ΔE 8.1 · #37474F

Nearest Bootstrap color

dark

Very different · ΔE 12.35 · #212529

OKLCH

Perceptual 50–950 scale

Generated in OKLCH from this hex. Not an official Tailwind scale unless the hex itself is a Tailwind token.

50e6f7ff 100d8eafe 200c1d7ee 300a9c1da 4008aa4c1 5006f89a4 6005c728a 700495b6f 800364555 90024303d 950111c26

Palette

Tints & shades

Full scale from light tints through the base color into deep shades

edeff1 dbdfe3 c9cfd5 b7bfc7 a5afb9 949fab 828f9d 707f8f 5e6f81 4c5f73 3a4f65 283f57 253a50 213549 1e2f41 1b2a3a 172533 14202c 111a24 0d151d 0a1016 070a0e 030507

Palette

Tints

Mixed toward white — soft backgrounds and highlights

edeff1 dbdfe3 c9cfd5 b7bfc7 a5afb9 949fab 828f9d 707f8f 5e6f81 4c5f73 3a4f65

Palette

Shades

Mixed toward black — depth, text, and emphasis

253a50 213549 1e2f41 1b2a3a 172533 14202c 111a24 0d151d 0a1016 070a0e 030507

Palette

Tones

Mixed toward neutral grey — muted UI surfaces

2f445a 374a5e 3e4f61 455565 4d5a68 54606c 5b656f 636a72 6a7076 717579 797b7d

Harmony

Complementary

Opposite on the color wheel for contrast

#283F57Stop 1 #574128Stop 2

Harmony

Analogous

Neighbors that sit comfortably together

#285757Stop 1 #283F57Stop 2 #292857Stop 3

Harmony

Triadic

Evenly spaced triad for vibrant sets

#283F57Stop 1 #57283FStop 2 #3F5728Stop 3

Harmony

Split complementary

Base plus two accents beside the complement

#283F57Stop 1 #572928Stop 2 #575728Stop 3

Harmony

Monochromatic

Same hue, varied lightness and saturation

#203246Stop 1 #38587AStop 2 #507EAFStop 3 #85A5C7Stop 4 #B9CBDFStop 5

Using this color

Where #283f57 works

#283F57 (#283f57) sits in the blue family at about 211° hue, 37% saturation, and 25% lightness. Contrast is 10.83:1 on white and 1.94:1 on black, so white labels read more clearly on the swatch itself. Nearest Tailwind token: slate-700 (approximation unless the hex is an official scale stop).

Sensible jobs for this swatch

supporting UI accents
text or icons on a white canvas

On a black or near-black UI, #283f57 is 1.94:1. 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.

Similar & related colors

Nearby colors from the library by perceptual distance

Midnight Blue#2C3E50 Tailwind slate 700#334155 Wet Asphalt#34495E Tailwind gray 700#374151 Tailwind sky 950#082F49 Spectrum #1A4675#1A4675 Tailwind sky 900#0C4A6E Spectrum #324771#324771 Web Safe #003366#003366 Spectrum #2F4E79#2F4E79 Spectrum #164E79#164E79 Spectrum #123D87#123D87