00FFFF (aqua) — RGB, HSL, CMYK and Contrast

Q: What text colour should sit on 00FFFF?

Black gives 16.75:1 and white gives 1.25:1, so black wins at 16.75:1. That clears the 4.5:1 AA threshold for normal text and the 7:1 AAA threshold as well.

Every value recomputed from the hex code · WCAG 2.1 contrast ratios

A teal at 50% lightness and 100% saturation, which puts it at 1.25:1 against white and 16.75:1 against black. The tables below give the notation conversions, the tints and shades that keep the hue intact, and the harmonies that pair with it.

00FFFF

Notation conversions

Notation	Value
HEX	`00FFFF`
RGB	rgb(0, 255, 255)
HSL	hsl(180, 100%, 50%)
CMYK	cmyk(100%, 0%, 0%, 0%)
Relative luminance	0.7874
Perceived brightness	70.1 / 100

R=0 G=255 B=255 · hue 180.0° · saturation 100.0% · lightness 50.0%

Contrast against pure white and pure black

Pair this colour with the two extremes to see which is the safer text partner. AA needs 4.5:1 for body text and 3:1 for large text; AAA raises that to 7:1 and 4.5:1.

Against	Hex	Ratio	AA text	AA large	AAA text
#FFFFFF	`white`	1.25:1	fail	fail	fail
#000000	`black`	16.75:1	pass	pass	pass

Tints and shades

Lightness moves in ten-point steps while hue and saturation stay fixed, which keeps the colour recognisable in a scale. The last column is the ratio against white text, useful for deciding where a scale stops working as a background.

Step	Hex	HSL	vs white text
shade -30	`#006666`	hsl(180, 100%, 20%)	6.79:1
shade -20	`#009999`	hsl(180, 100%, 30%)	3.49:1
shade -10	`#00cccc`	hsl(180, 100%, 40%)	2.00:1
tint +10	`#33ffff`	hsl(180, 100%, 60%)	1.24:1
tint +20	`#66ffff`	hsl(180, 100%, 70%)	1.21:1
tint +30	`#99ffff`	hsl(180, 100%, 80%)	1.16:1

Harmonies

Scheme	Hex
Complementary	`#ff0000`
Analogous −30	`#00ff80`
Analogous +30	`#0080ff`
Triadic −120	`#ffff00`
Triadic +120	`#ff00ff`

Read back from the notation table, 00FFFF is rgb(0, 255, 255), which normalises to hue 180.0° at 100.0% saturation and 50.0% lightness. Its relative luminance of 0.7874 is what produces the two ratios above: 1.25:1 against white and 16.75:1 against black, a gap of 15.49. Position 33 of 69 in the colour library, it darkens to #006666 thirty points lower on the lightness axis and lifts to #99ffff thirty higher, while the complementary rotation lands on #ff0000.

Nearby colours

00BCD4 Cyan 500 607D8B Blue Grey 500 03A9F4 Light Blue 500 40E0D0 turquoise 87CEEB skyblue 000080 navy

Frequently asked questions

What text colour should sit on 00FFFF?
Black gives 16.75:1 and white gives 1.25:1, so black wins at 16.75:1. That clears the 4.5:1 AA threshold for normal text and the 7:1 AAA threshold as well.

Do the CMYK numbers match a print workflow?
They are the naive conversion from RGB, which assumes no ink limit, no colour profile and no black generation strategy. Real print work needs a profile-aware conversion; the values here are the ones the converter reports and are best used as a starting point for a designer rather than a press-ready separations file.

Convert any other colour, or test a pair against each other, in the ColrShift colour converter and contrast checker. The colour library groups every entry on this site by hue family.