Inspect Lime (#00FF00) in HEX, RGB, HSL, LCH and OKLCH, check its contrast, and copy the value you need.
Lime
#00FF00
Black text reads best on this background, at 15.3:1.
Lime is one of the 148 CSS named colors, and resolves to #00FF00 in every browser. In numbers that is rgb(0, 255, 0) and hsl(120, 100%, 50%). Perceptually it is a light, vivid color: OKLCH puts its lightness at 87% and its chroma at 0.295. It sits in the greens at 142 degrees of OKLCH hue, and reads as a cool color.
White text only reaches 1.37:1 here, so black text is the safer pairing at 15.3:1. At this chroma it is loud enough to be an accent or a call to action, but it will fight anything else vivid placed next to it.
The closest CSS named colors to Lime, measured with CIEDE2000, are LawnGreen (#7CFC00), Chartreuse (#7FFF00), SpringGreen (#00FF7F). If Lime is not quite right, those are the nearest keywords to try before reaching for a custom value.
HEX
#00FF00
RGB
rgb(0, 255, 0)
HSL
hsl(120, 100%, 50%)
HWB
hwb(120 0% 0%)
CMYK
cmyk(100%, 0%, 100%, 0%)
LAB
lab(87.82 -79.27 80.99)
LCH
lch(87.82 113.33 134.38)
OKLCH
oklch(86.64% 0.2948 142.5)
WCAG asks for 4.5:1 between body text and its background. On #00FF00 white text measures 1.37:1 and black text 15.3:1, so black clears it and white does not.
White text on Lime
WCAG 2.2
1.37:1
APCA
Lc 19
Fails AA body text
Fails AAA body text
Fails AA large text
Black text on Lime
WCAG 2.2
15.3:1
APCA
Lc 86
Passes AA body text
Passes AAA body text
Passes AA large text
Check Lime against any other color in the contrast checker.
Lime sits at 87% OKLCH lightness. Holding its hue and chroma and moving only that value carries it up to #ECFFE9 and down to #000900, which keeps the family recognizable instead of letting it drift toward gray the way a plain HSL ramp does.
#6EFF66
20% lighter
#98FF91
40% lighter
#B9FFB2
60% lighter
#D4FFCF
80% lighter
#ECFFE9
100% lighter
#00C600
20% darker
#009100
40% darker
#005E00
60% darker
#003000
80% darker
#000900
100% darker
Build a full accessible scale from #00FF00 in the shade generator.
Hues rotated around #00FF00 in OKLCH, then pulled back into the sRGB gamut. Each swatch is labelled with the nearest CSS named color so you have a keyword to start from.
Lime sits at 142 degrees. Rotating it a half turn lands on 322 degrees, the hue directly opposite. It is the strongest pairing you can make without changing lightness, and the one most likely to vibrate if you use both at full chroma.
The neighbors of Lime at 112 and 172 degrees. They stay close enough to read as the same family, which is what you want for hover states, secondary surfaces and gradients.
142, 262 and 22 degrees divide the wheel into thirds. Balanced enough to carry a whole palette without one color dominating the other two.
Instead of the complement at 322 degrees, this pair flanks it at 292 and 352. You keep most of the contrast of a complementary pairing while losing the harshness.
Explore more combinations around Lime on the color wheel.
The biggest shift is under deuteranopia, where #00FF00 reads as #DBAB0B, 37.1 CIEDE2000 units away. If Lime is the only thing marking a state or a series, roughly one viewer in twelve will miss it.
Protanopia
#FFC900
Deuteranopia
#DBAB0B
Tritanopia
#00EDB0
Achromatopsia
#B6B6B6
The nearest CSS keywords to #00FF00, ranked by perceptual distance rather than by how close their hex digits happen to look.