Inspect LightSlateGray (#778899) in HEX, RGB, HSL, LCH and OKLCH, check its contrast, and copy the value you need.
LightSlateGray
#778899
Black text reads best on this background, at 5.77:1.
LightSlateGray is one of the 148 CSS named colors, and resolves to #778899 in every browser. In numbers that is rgb(119, 136, 153) and hsl(210, 14%, 53%). Perceptually it is a mid-toned, near-neutral color: OKLCH puts its lightness at 62% and its chroma at 0.032. It carries almost no chroma, so it behaves as a neutral rather than as a hue, and belongs with the grays.
White text only reaches 3.64:1 here, so black text is the safer pairing at 5.77:1. With this little chroma it recedes, which makes it useful for borders, dividers and secondary surfaces.
The closest CSS named colors to LightSlateGray, measured with CIEDE2000, are SlateGray (#708090), SlateGrey (#708090), Gray (#808080). If LightSlateGray is not quite right, those are the nearest keywords to try before reaching for a custom value.
HEX
#778899
RGB
rgb(119, 136, 153)
HSL
hsl(210, 14%, 53%)
HWB
hwb(210 47% 40%)
CMYK
cmyk(22%, 11%, 0%, 40%)
LAB
lab(55.77 -3.45 -11.29)
LCH
lch(55.77 11.8 253.02)
OKLCH
oklch(61.9% 0.0325 248.35)
WCAG asks for 4.5:1 between body text and its background. On #778899 white text measures 3.64:1 and black text 5.77:1, so black clears it and white does not.
White text on LightSlateGray
WCAG 2.2
3.64:1
APCA
Lc 69
Fails AA body text
Fails AAA body text
Passes AA large text
Black text on LightSlateGray
WCAG 2.2
5.77:1
APCA
Lc 40
Passes AA body text
Fails AAA body text
Passes AA large text
Check LightSlateGray against any other color in the contrast checker.
LightSlateGray sits at 62% OKLCH lightness. Holding its hue and chroma and moving only that value carries it up to #F3F9FF and down to #000611, which keeps the family recognizable instead of letting it drift toward gray the way a plain HSL ramp does.
#8D9EAF
20% lighter
#A3B4C6
40% lighter
#B9CBDE
60% lighter
#D0E3F6
80% lighter
#F3F9FF
100% lighter
#5A6B7B
20% darker
#3F4F5E
40% darker
#263443
60% darker
#0E1C29
80% darker
#000611
100% darker
Build a full accessible scale from #778899 in the shade generator.
Hues rotated around #778899 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.
LightSlateGray sits at 248 degrees. Rotating it a half turn lands on 68 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 LightSlateGray at 218 and 278 degrees. They stay close enough to read as the same family, which is what you want for hover states, secondary surfaces and gradients.
248, 8 and 128 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 68 degrees, this pair flanks it at 38 and 98. You keep most of the contrast of a complementary pairing while losing the harshness.
Explore more combinations around LightSlateGray on the color wheel.
The biggest shift is under tritanopia, where #778899 reads as #708C8D, 10 CIEDE2000 units away. If LightSlateGray is the only thing marking a state or a series, roughly one viewer in twelve will miss it.
Protanopia
#82889A
Deuteranopia
#7E8499
Tritanopia
#708C8D
Achromatopsia
#868686
The nearest CSS keywords to #778899, ranked by perceptual distance rather than by how close their hex digits happen to look.