#42D8EA
Closest named color: Aqua Blue (#02D8E9). oklch(81.3% 0.124 206.8), rgb(66, 216, 234).
Aa
Black text reads best on this color (12.24:1).
About this color
#42D8EA is a light, moderately saturated teal or cyan. In OKLCH its lightness is 81%, its chroma 0.124 and its hue 207°. Its hue sits on the cool side of the wheel. The nearest named color is Aqua Blue (#02D8E9), ΔE 0.016 away. Black text reads best on it, at 12.24:1.
| Hue family | Teals and cyans |
| Lightness | light (81%) |
| Chroma | moderately saturated (0.124) |
| Temperature | cool |
| Nearest name | Aqua Blue (#02D8E9) |
| Black text | 12.24:1 |
| White text | 1.71:1 |
Values
| HEX | #42D8EA |
| RGB | rgb(66, 216, 234) |
| HSL | hsl(186, 80%, 59%) |
| OKLCH | oklch(81.3% 0.124 206.8) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #42D8EA | 1.71:1 | Fails | Lc -34.3 | Non-text elements, placeholder text |
| Black text on #42D8EA | 12.24:1 | AAA | Lc 73.4 | Content text, not long reading |
| #42D8EA text on white | 1.71:1 | Fails | Lc 30.5 | Non-text elements, placeholder text |
| #42D8EA text on black | 12.24:1 | AAA | Lc -72.3 | Content text, not long reading |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 300.
-
Step 50
50
#E9F9FB
oklch(97.1% 0.017 205.8)
-
Step 100
100
#CFF1F6
oklch(93.5% 0.036 207.4)
-
Step 200
200
#A3E7F0
oklch(88.6% 0.069 206.3)
-
Step 300
300 (this color)
#42D8EA
oklch(81.3% 0.124 206.8)
-
Step 400
400
#00B5C6
oklch(70.6% 0.121 206.7)
-
Step 500
500
#009BAA
oklch(63% 0.108 206.9)
-
Step 600
600
#00838F
oklch(55.7% 0.095 206.1)
-
Step 700
700
#006E79
oklch(49.2% 0.084 206.9)
-
Step 800
800
#005A63
oklch(42.7% 0.073 206.6)
-
Step 900
900
#004B53
oklch(37.7% 0.065 207)
-
Step 950
950
#002D32
oklch(27.1% 0.046 206.3)
#42D8EA with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #C6D0EB | 0.121 |
| Deuteranopia (no green cones) | #AEBEEA | 0.111 |
| Tritanopia (no blue cones) | #00E1DD | 0.038 |
| Achromatopsia (no color) | #C6C6C6 | 0.125 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42D8EA
#42D8EA
oklch(81.3% 0.124 206.8)
- #FFA79D
#FFA79D
oklch(81.3% 0.106 26.7)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #42D8EA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Aqua Blue #02D8E9 ΔE 0.016
- Medium Turquoise #48D1CC ΔE 0.042
- Vivid Sky Blue #4CC9F0 ΔE 0.045
- Dark Turquoise #00CED1 ΔE 0.047
- Turquoise #40E0D0 ΔE 0.050
- Bright Sky Blue #02CCFE ΔE 0.054
- Sky Blue #87CEEB ΔE 0.054
- Lightblue #7BC8F6 ΔE 0.062
Use #42D8EA in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.