Classic Onyx Black
A versatile very dark neutral.
#373737
rgb(55, 55, 55)
Color formats
HEX
#373737
RGB
rgb(55, 55, 55)
HSL
hsl(0, 0%, 21.6%)
HSV
hsv(0, 0%, 21.6%)
CMYK
cmyk(0%, 0%, 0%, 78.4%)
Color shades
Lighter tints and darker shades of Classic Onyx Black.
Lightest
#9D9D9D
Lighter
#6A6A6A
Base
#373737
Darker
#040404
Darkest
#000000
Complementary
The opposite hue on the color wheel.
Analogous
Neighbouring hues that harmonise.
Contrast & readability
Where Classic Onyx Black works
Classic Onyx Black (#373737) is a versatile very dark neutral. As a deep tone it works well for text, headers and high-contrast backgrounds where you want weight and focus. The low saturation keeps it calm and easy to pair, so it sits comfortably next to almost any accent color.
Observe the spectrum
More colors related to Classic Onyx Black — or browse all blacks.
Color tools
Color Format Converter
Convert any color between HEX, RGB, HSL, HSV, CMYK and OKLCH instantly — and copy ready-to-paste CSS, SCSS or Tailwind.
Color Picker
Pick any color visually and copy accurate HEX, RGB, HSL and CMYK codes — no signup.
Palette Generator
Generate harmonious color palettes from any base color — complementary, analogous, triadic and more, with instant CSS export.
Contrast Checker
Test color contrast against WCAG 2.1 AA/AAA — live pass/fail, font-size rules, and a real component preview.
Shade & Tint Generator
Generate 10–12 step tints and shades from any color — perfect 50–950 UI ramps with CSS and Tailwind export.
Complementary Color Finder
Find the perfect complementary (180° opposite) color for any shade, with HEX/RGB/HSL and contrast info.