Inspect LightSkyBlue (#87CEFA) in HEX, RGB, HSL, LCH and OKLCH, check its contrast, and copy the value you need.
LightSkyBlue
#87CEFA
Black text reads best on this background, at 12.24:1.
LightSkyBlue is one of the 148 CSS named colors, and resolves to #87CEFA in every browser. In numbers that is rgb(135, 206, 250) and hsl(203, 92%, 75%). Perceptually it is a light, muted color: OKLCH puts its lightness at 82% and its chroma at 0.095. It sits in the blues at 237 degrees of OKLCH hue, and reads as a cool color.
White text only reaches 1.72:1 here, so black text is the safer pairing at 12.24:1. That combination of lightness and chroma makes it a workable mid-tone, the kind of value that lands in the middle of a shade scale.
The closest CSS named colors to LightSkyBlue, measured with CIEDE2000, are SkyBlue (#87CEEB), DeepSkyBlue (#00BFFF), LightBlue (#ADD8E6). If LightSkyBlue is not quite right, those are the nearest keywords to try before reaching for a custom value.
HEX
#87CEFA
RGB
rgb(135, 206, 250)
HSL
hsl(203, 92%, 75%)
HWB
hwb(203 53% 2%)
CMYK
cmyk(46%, 18%, 0%, 2%)
LAB
lab(79.29 -14.43 -29.1)
LCH
lch(79.29 32.48 243.62)
OKLCH
oklch(82.06% 0.0945 236.75)
WCAG asks for 4.5:1 between body text and its background. On #87CEFA white text measures 1.72:1 and black text 12.24:1, so black clears it and white does not.
White text on LightSkyBlue
WCAG 2.2
1.72:1
APCA
Lc 34
Fails AA body text
Fails AAA body text
Fails AA large text
Black text on LightSkyBlue
WCAG 2.2
12.24:1
APCA
Lc 73
Passes AA body text
Passes AAA body text
Passes AA large text
Check LightSkyBlue against any other color in the contrast checker.
LightSkyBlue sits at 82% OKLCH lightness. Holding its hue and chroma and moving only that value carries it up to #F2FAFF and down to #00070E, which keeps the family recognizable instead of letting it drift toward gray the way a plain HSL ramp does.
#99D8FF
20% lighter
#B1E0FF
40% lighter
#C7E9FF
60% lighter
#DDF1FF
80% lighter
#F2FAFF
100% lighter
#5BA1CB
20% darker
#2E769F
40% darker
#004E70
60% darker
#00273C
80% darker
#00070E
100% darker
Build a full accessible scale from #87CEFA in the shade generator.
Hues rotated around #87CEFA 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.
LightSkyBlue sits at 237 degrees. Rotating it a half turn lands on 57 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 LightSkyBlue at 207 and 267 degrees. They stay close enough to read as the same family, which is what you want for hover states, secondary surfaces and gradients.
237, 357 and 117 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 57 degrees, this pair flanks it at 27 and 87. You keep most of the contrast of a complementary pairing while losing the harshness.
Explore more combinations around LightSkyBlue on the color wheel.
The biggest shift is under achromatopsia, where #87CEFA reads as #C2C2C2, 18.7 CIEDE2000 units away. If LightSkyBlue is the only thing marking a state or a series, roughly one viewer in twelve will miss it.
Protanopia
#BACAFD
Deuteranopia
#AABCF9
Tritanopia
#6DDADB
Achromatopsia
#C2C2C2
The nearest CSS keywords to #87CEFA, ranked by perceptual distance rather than by how close their hex digits happen to look.