Inspect DarkTurquoise (#00CED1) in HEX, RGB, HSL, LCH and OKLCH, check its contrast, and copy the value you need.
DarkTurquoise
#00CED1
Black text reads best on this background, at 10.75:1.
DarkTurquoise is one of the 148 CSS named colors, and resolves to #00CED1 in every browser. In numbers that is rgb(0, 206, 209) and hsl(181, 100%, 41%). Perceptually it is a light, moderately saturated color: OKLCH puts its lightness at 77% and its chroma at 0.131. It sits in the cyans at 197 degrees of OKLCH hue, and reads as a cool color.
White text only reaches 1.95:1 here, so black text is the safer pairing at 10.75:1. 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 DarkTurquoise, measured with CIEDE2000, are MediumTurquoise (#48D1CC), Turquoise (#40E0D0), LightSeaGreen (#20B2AA). If DarkTurquoise is not quite right, those are the nearest keywords to try before reaching for a custom value.
HEX
#00CED1
RGB
rgb(0, 206, 209)
HSL
hsl(181, 100%, 41%)
HWB
hwb(181 0% 18%)
CMYK
cmyk(100%, 1%, 0%, 18%)
LAB
lab(74.9 -42.43 -14.23)
LCH
lch(74.9 44.75 198.54)
OKLCH
oklch(77.19% 0.1314 196.64)
WCAG asks for 4.5:1 between body text and its background. On #00CED1 white text measures 1.95:1 and black text 10.75:1, so black clears it and white does not.
White text on DarkTurquoise
WCAG 2.2
1.95:1
APCA
Lc 41
Fails AA body text
Fails AAA body text
Fails AA large text
Black text on DarkTurquoise
WCAG 2.2
10.75:1
APCA
Lc 67
Passes AA body text
Passes AAA body text
Passes AA large text
Check DarkTurquoise against any other color in the contrast checker.
DarkTurquoise sits at 77% OKLCH lightness. Holding its hue and chroma and moving only that value carries it up to #E3FFFF and down to #000808, which keeps the family recognizable instead of letting it drift toward gray the way a plain HSL ramp does.
#2DDCDF
20% lighter
#44EAEC
40% lighter
#57F8FA
60% lighter
#9FFEFF
80% lighter
#E3FFFF
100% lighter
#00A1A3
20% darker
#007577
40% darker
#004D4E
60% darker
#002829
80% darker
#000808
100% darker
Build a full accessible scale from #00CED1 in the shade generator.
Hues rotated around #00CED1 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.
DarkTurquoise sits at 197 degrees. Rotating it a half turn lands on 17 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 DarkTurquoise at 167 and 227 degrees. They stay close enough to read as the same family, which is what you want for hover states, secondary surfaces and gradients.
197, 317 and 77 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 17 degrees, this pair flanks it at 347 and 47. You keep most of the contrast of a complementary pairing while losing the harshness.
Explore more combinations around DarkTurquoise on the color wheel.
The biggest shift is under deuteranopia, where #00CED1 reads as #8294D3, 30.6 CIEDE2000 units away. If DarkTurquoise is the only thing marking a state or a series, roughly one viewer in twelve will miss it.
Protanopia
#AEB7D2
Deuteranopia
#8294D3
Tritanopia
#00DFCE
Achromatopsia
#A2A2A2
The nearest CSS keywords to #00CED1, ranked by perceptual distance rather than by how close their hex digits happen to look.