#66cc00

Color values Color notations — HEX (hexadecimal), RGB (light primaries), HSL (hue/saturation/lightness), CMYK (print inks, approximate).

HEX
#66cc00
RGB
rgb(102, 204, 0)
HSL
hsl(90, 100%, 40%)
OKLCH
oklch(75.3% 0.223 135.8)
CMYK
50% 0% 100% 20%
Relative luminance Relative luminance: a color's brightness from 0 (black) to 1 (white). It is used to compute WCAG contrast.
0.4601
Hue Hue: the kind of a color (red, orange, yellow…). We group the hue wheel into 12 sectors.
Chartreuse
Nearest name Nearest name: the closest CSS standard color name to this color.
lawngreen

Contrast

Ratio Contrast ratio: the brightness difference between two colors, from 1:1 to 21:1. Higher is easier to read. APCA (Lc) APCA: a newer perceptual contrast measure from the WCAG 3 draft. Lc runs about 0–106; higher is easier to read. The sign shows polarity (dark text on light, or light on dark).
As background
White text 2.06:1 -44
Black text 10.2:1 64
As text
White background 2.06:1 40
Black background 10.2:1 -63

Color harmonies

Complementary Complementary: the opposite color on the wheel (180°). The two make each other pop.

Analogous Analogous: neighbors on the wheel (about ±15°). They make a cohesive palette.

Triadic Triadic: three colors evenly spaced 120° apart. Balanced and lively.

Split complementary Split complementary: the two colors beside the complement (180° ± 30°). Softer than a straight complement.

Tetradic Tetradic: four colors evenly spaced 90° apart. Good for multi-accent palettes.

Tone scale Tone scale: five steps that keep the hue but vary the lightness.

Shades & tints Shades & tints: lighter steps mixed toward white (tints) and darker steps mixed toward black (shades).

Impressions Impression: a tag for the mood a color evokes — warm, calm, vivid and so on.

Usage preview

As background (black text)

Ratio 10.2:1 APCA (Lc) 64

As background (white text)

Ratio 2.06:1 APCA (Lc) -44

As text (white background)

Ratio 2.06:1 APCA (Lc) 40

As text (black background)

Ratio 10.2:1 APCA (Lc) -63