Inspect CadetBlue (#5F9EA0) in HEX, RGB, HSL, LCH and OKLCH, check its contrast, and copy the value you need.
CadetBlue
#5F9EA0
Black text reads best on this background, at 6.88:1.
CadetBlue is one of the 148 CSS named colors, and resolves to #5F9EA0 in every browser. In numbers that is rgb(95, 158, 160) and hsl(182, 25%, 50%). Perceptually it is a mid-toned, muted color: OKLCH puts its lightness at 66% and its chroma at 0.065. It sits in the cyans at 198 degrees of OKLCH hue, and reads as a cool color.
White text only reaches 3.05:1 here, so black text is the safer pairing at 6.88:1. 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 CadetBlue, measured with CIEDE2000, are LightSeaGreen (#20B2AA), DarkCyan (#008B8B), Teal (#008080). If CadetBlue is not quite right, those are the nearest keywords to try before reaching for a custom value.
HEX
#5F9EA0
RGB
rgb(95, 158, 160)
HSL
hsl(182, 25%, 50%)
HWB
hwb(182 37% 37%)
CMYK
cmyk(41%, 1%, 0%, 37%)
LAB
lab(60.95 -20.74 -7.79)
LCH
lch(60.95 22.16 200.59)
OKLCH
oklch(65.77% 0.065 198.3)
WCAG asks for 4.5:1 between body text and its background. On #5F9EA0 white text measures 3.05:1 and black text 6.88:1, so black clears it and white does not.
White text on CadetBlue
WCAG 2.2
3.05:1
APCA
Lc 62
Fails AA body text
Fails AAA body text
Passes AA large text
Black text on CadetBlue
WCAG 2.2
6.88:1
APCA
Lc 46
Passes AA body text
Fails AAA body text
Passes AA large text
Check CadetBlue against any other color in the contrast checker.
CadetBlue sits at 66% OKLCH lightness. Holding its hue and chroma and moving only that value carries it up to #E5FEFF and down to #000808, which keeps the family recognizable instead of letting it drift toward gray the way a plain HSL ramp does.
#73B2B4
20% lighter
#87C7C9
40% lighter
#9BDCDE
60% lighter
#B0F1F3
80% lighter
#E5FEFF
100% lighter
#3E7D7F
20% darker
#1B5E60
40% darker
#003F41
60% darker
#002223
80% darker
#000808
100% darker
Build a full accessible scale from #5F9EA0 in the shade generator.
Hues rotated around #5F9EA0 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.
CadetBlue sits at 198 degrees. Rotating it a half turn lands on 18 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 CadetBlue at 168 and 228 degrees. They stay close enough to read as the same family, which is what you want for hover states, secondary surfaces and gradients.
198, 318 and 78 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 18 degrees, this pair flanks it at 348 and 48. You keep most of the contrast of a complementary pairing while losing the harshness.
Explore more combinations around CadetBlue on the color wheel.
The biggest shift is under deuteranopia, where #5F9EA0 reads as #868CA1, 20.4 CIEDE2000 units away. If CadetBlue is the only thing marking a state or a series, roughly one viewer in twelve will miss it.
Protanopia
#9497A0
Deuteranopia
#868CA1
Tritanopia
#4FA39E
Achromatopsia
#919191
The nearest CSS keywords to #5F9EA0, ranked by perceptual distance rather than by how close their hex digits happen to look.