Inspect SpringGreen (#00FF7F) in HEX, RGB, HSL, LCH and OKLCH, check its contrast, and copy the value you need.
SpringGreen
#00FF7F
Black text reads best on this background, at 15.61:1.
SpringGreen is one of the 148 CSS named colors, and resolves to #00FF7F in every browser. In numbers that is rgb(0, 255, 127) and hsl(150, 100%, 50%). Perceptually it is a light, vivid color: OKLCH puts its lightness at 87% and its chroma at 0.235. It sits in the greens at 151 degrees of OKLCH hue, and reads as a cool color.
White text only reaches 1.35:1 here, so black text is the safer pairing at 15.61:1. 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 SpringGreen, measured with CIEDE2000, are MediumSpringGreen (#00FA9A), PaleGreen (#98FB98), LightGreen (#90EE90). If SpringGreen is not quite right, those are the nearest keywords to try before reaching for a custom value.
HEX
#00FF7F
RGB
rgb(0, 255, 127)
HSL
hsl(150, 100%, 50%)
HWB
hwb(150 0% 0%)
CMYK
cmyk(100%, 0%, 50%, 0%)
LAB
lab(88.44 -72.5 45.98)
LCH
lch(88.44 85.85 147.62)
OKLCH
oklch(87.49% 0.2353 151.02)
WCAG asks for 4.5:1 between body text and its background. On #00FF7F white text measures 1.35:1 and black text 15.61:1, so black clears it and white does not.
White text on SpringGreen
WCAG 2.2
1.35:1
APCA
Lc 18
Fails AA body text
Fails AAA body text
Fails AA large text
Black text on SpringGreen
WCAG 2.2
15.61:1
APCA
Lc 87
Passes AA body text
Passes AAA body text
Passes AA large text
Check SpringGreen against any other color in the contrast checker.
SpringGreen sits at 87% OKLCH lightness. Holding its hue and chroma and moving only that value carries it up to #EAFFEE and down to #000802, which keeps the family recognizable instead of letting it drift toward gray the way a plain HSL ramp does.
#6CFF9A
20% lighter
#97FFB2
40% lighter
#B7FFC7
60% lighter
#D2FFDB
80% lighter
#EAFFEE
100% lighter
#00C661
20% darker
#009045
40% darker
#005E2B
60% darker
#003013
80% darker
#000802
100% darker
Build a full accessible scale from #00FF7F in the shade generator.
Hues rotated around #00FF7F 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.
SpringGreen sits at 151 degrees. Rotating it a half turn lands on 331 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 SpringGreen at 121 and 181 degrees. They stay close enough to read as the same family, which is what you want for hover states, secondary surfaces and gradients.
151, 271 and 31 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 331 degrees, this pair flanks it at 301 and 1. You keep most of the contrast of a complementary pairing while losing the harshness.
Explore more combinations around SpringGreen on the color wheel.
The biggest shift is under protanopia, where #00FF7F reads as #F2D579, 31.3 CIEDE2000 units away. If SpringGreen is the only thing marking a state or a series, roughly one viewer in twelve will miss it.
Protanopia
#F2D579
Deuteranopia
#BFB286
Tritanopia
#00FFD7
Achromatopsia
#BFC0BF
The nearest CSS keywords to #00FF7F, ranked by perceptual distance rather than by how close their hex digits happen to look.