Inspect LightGray (#D3D3D3) in HEX, RGB, HSL, LCH and OKLCH, check its contrast, and copy the value you need.
LightGray
#D3D3D3
Black text reads best on this background, at 14.03:1.
LightGray is one of the 148 CSS named colors, and resolves to #D3D3D3 in every browser. In numbers that is rgb(211, 211, 211) and hsl(0, 0%, 83%). Perceptually it is a light, near-neutral color: OKLCH puts its lightness at 87% and its chroma at 0. 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 1.5:1 here, so black text is the safer pairing at 14.03:1. With this little chroma it recedes, which makes it useful for borders, dividers and secondary surfaces.
The closest CSS named colors to LightGray, measured with CIEDE2000, are Gainsboro (#DCDCDC), Silver (#C0C0C0), WhiteSmoke (#F5F5F5). If LightGray is not quite right, those are the nearest keywords to try before reaching for a custom value.
HEX
#D3D3D3
RGB
rgb(211, 211, 211)
HSL
hsl(0, 0%, 83%)
HWB
hwb(0 83% 17%)
CMYK
cmyk(0%, 0%, 0%, 17%)
LAB
lab(84.56 0 0)
LCH
lch(84.56 0 0)
OKLCH
oklch(86.69% 0 0)
WCAG asks for 4.5:1 between body text and its background. On #D3D3D3 white text measures 1.5:1 and black text 14.03:1, so black clears it and white does not.
White text on LightGray
WCAG 2.2
1.5:1
APCA
Lc 26
Fails AA body text
Fails AAA body text
Fails AA large text
Black text on LightGray
WCAG 2.2
14.03:1
APCA
Lc 80
Passes AA body text
Passes AAA body text
Passes AA large text
Check LightGray against any other color in the contrast checker.
LightGray sits at 87% OKLCH lightness. Holding its hue and chroma and moving only that value carries it up to #F8F8F8 and down to #060606, which keeps the family recognizable instead of letting it drift toward gray the way a plain HSL ramp does.
#DADADA
20% lighter
#E2E2E2
40% lighter
#E9E9E9
60% lighter
#F1F1F1
80% lighter
#F8F8F8
100% lighter
#A4A4A4
20% darker
#777777
40% darker
#4D4D4D
60% darker
#262626
80% darker
#060606
100% darker
Build a full accessible scale from #D3D3D3 in the shade generator.
LightGray barely moves under any of the four common forms of color blindness, the largest shift being 0 CIEDE2000 units under protanopia. It stays recognizable, though it still should not be the only thing carrying meaning.
Protanopia
#D3D3D3
Deuteranopia
#D3D3D3
Tritanopia
#D3D3D3
Achromatopsia
#D3D3D3
The nearest CSS keywords to #D3D3D3, ranked by perceptual distance rather than by how close their hex digits happen to look.