Aqua is the CSS named color #00FFFF — rgb(0, 255, 255), hsl(180, 100%, 50%). Its relative luminance is 0.787, giving 1.25:1 against white and 16.75:1 against black, so it works as a text color on black.
| HEX | #00FFFF |
|---|---|
| RGB | rgb(0, 255, 255) |
| HSL | hsl(180, 100%, 50%) |
| Relative luminance | 0.7874 |
| Contrast on white | 1.25:1 AA fail |
| Contrast on black | 16.75:1 AA pass |
Built by mixing aqua toward white (four steps) and toward black (four steps) while keeping the hue. Use the shades generator for a different step count or to add harmony sets.
Closest by CIELAB distance (ΔE76). For perceptual matching in a design system, compare in OKLab before locking a token.
aqua is #00FFFF, which is rgb(0, 255, 255) and hsl(180, 100%, 50%). It is one of the 148 CSS named colors defined by the CSS Color Module Level 4.
Aqua has a relative luminance of 0.787 on a 0–1 scale, so it is a light color. Against white it scores 1.25:1; against black, 16.75:1.
aqua reaches 16.75:1 against black, which clears WCAG 2.2 AA for normal text (4.5:1) at any size.