Inspect DarkSlateBlue (#483D8B) in HEX, RGB, HSL, LCH and OKLCH, check its contrast, and copy the value you need.
DarkSlateBlue
#483D8B
White text reads best on this background, at 9.07:1.
DarkSlateBlue is one of the 148 CSS named colors, and resolves to #483D8B in every browser. In numbers that is rgb(72, 61, 139) and hsl(248, 39%, 39%). Perceptually it is a dark, moderately saturated color: OKLCH puts its lightness at 41% and its chroma at 0.125. It sits in the purples at 286 degrees of OKLCH hue, and reads as a cool color.
White text clears WCAG AA on a DarkSlateBlue background at 9.07:1, and AAA as well. 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 DarkSlateBlue, measured with CIEDE2000, are RebeccaPurple (#663399), MidnightBlue (#191970), Indigo (#4B0082). If DarkSlateBlue is not quite right, those are the nearest keywords to try before reaching for a custom value.
HEX
#483D8B
RGB
rgb(72, 61, 139)
HSL
hsl(248, 39%, 39%)
HWB
hwb(248 24% 45%)
CMYK
cmyk(48%, 56%, 0%, 45%)
LAB
lab(30.28 21.41 -42.74)
LCH
lch(30.28 47.81 296.61)
OKLCH
oklch(41.43% 0.1248 286.04)
WCAG asks for 4.5:1 between body text and its background. On #483D8B white text measures 9.07:1 and black text 2.32:1, so white clears it and black does not.
White text on DarkSlateBlue
WCAG 2.2
9.07:1
APCA
Lc 95
Passes AA body text
Passes AAA body text
Passes AA large text
Black text on DarkSlateBlue
WCAG 2.2
2.32:1
APCA
Lc 13
Fails AA body text
Fails AAA body text
Fails AA large text
Check DarkSlateBlue against any other color in the contrast checker.
DarkSlateBlue sits at 41% OKLCH lightness. Holding its hue and chroma and moving only that value carries it up to #F8F8FF and down to #06001F, which keeps the family recognizable instead of letting it drift toward gray the way a plain HSL ramp does.
#665EAF
20% lighter
#8780D4
40% lighter
#A9A3FB
60% lighter
#CFCDFF
80% lighter
#F8F8FF
100% lighter
#392C79
20% darker
#2C1B67
40% darker
#1F0755
60% darker
#12003B
80% darker
#06001F
100% darker
Build a full accessible scale from #483D8B in the shade generator.
Hues rotated around #483D8B 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.
DarkSlateBlue sits at 286 degrees. Rotating it a half turn lands on 106 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 DarkSlateBlue at 256 and 316 degrees. They stay close enough to read as the same family, which is what you want for hover states, secondary surfaces and gradients.
286, 46 and 166 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 106 degrees, this pair flanks it at 76 and 136. You keep most of the contrast of a complementary pairing while losing the harshness.
Explore more combinations around DarkSlateBlue on the color wheel.
The biggest shift is under achromatopsia, where #483D8B reads as #454545, 23.9 CIEDE2000 units away. If DarkSlateBlue is the only thing marking a state or a series, roughly one viewer in twelve will miss it.
Protanopia
#2F468F
Deuteranopia
#2F4488
Tritanopia
#3D4855
Achromatopsia
#454545
The nearest CSS keywords to #483D8B, ranked by perceptual distance rather than by how close their hex digits happen to look.