#42DEFF
Closest named color: Aqua Blue (#02D8E9). oklch(83.5% 0.133 215.4), rgb(66, 222, 255).
Aa
Black text reads best on this color (13.12:1).
About this color
#42DEFF is a light, moderately saturated teal or cyan. In OKLCH its lightness is 83%, its chroma 0.133 and its hue 215°. Its hue sits on the cool side of the wheel. The nearest named color is Aqua Blue (#02D8E9), ΔE 0.039 away. Black text reads best on it, at 13.12:1.
| Hue family | Teals and cyans |
| Lightness | light (83%) |
| Chroma | moderately saturated (0.133) |
| Temperature | cool |
| Nearest name | Aqua Blue (#02D8E9) |
| Black text | 13.12:1 |
| White text | 1.60:1 |
Values
| HEX | #42DEFF |
| RGB | rgb(66, 222, 255) |
| HSL | hsl(190, 100%, 63%) |
| OKLCH | oklch(83.5% 0.133 215.4) |
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 #42DEFF | 1.60:1 | Fails | Lc -30.1 | Non-text elements, placeholder text |
| Black text on #42DEFF | 13.12:1 | AAA | Lc 77.1 | Fine for body text |
| #42DEFF text on white | 1.60:1 | Fails | Lc 26.6 | Dividers and decoration only |
| #42DEFF text on black | 13.12:1 | AAA | Lc -76.4 | Fine for body text |
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
#E9F9FD
oklch(97.1% 0.018 214.4)
-
Step 100
100
#CEF1FA
oklch(93.6% 0.038 215)
-
Step 200
200
#A0E6F8
oklch(88.5% 0.074 215.6)
-
Step 300
300 (this color)
#42DEFF
oklch(83.5% 0.133 215.4)
-
Step 400
400
#00B3D1
oklch(70.6% 0.125 215.4)
-
Step 500
500
#009AB4
oklch(63.2% 0.112 215.3)
-
Step 600
600
#008197
oklch(55.5% 0.098 215.2)
-
Step 700
700
#006D80
oklch(49.2% 0.087 215.3)
-
Step 800
800
#005969
oklch(42.7% 0.076 215.4)
-
Step 900
900
#004A58
oklch(37.7% 0.067 215.8)
-
Step 950
950
#002C35
oklch(27% 0.048 215.4)
#42DEFF 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) | #C7D7FF | 0.117 |
| Deuteranopia (no green cones) | #AEC4FF | 0.107 |
| Tritanopia (no blue cones) | #00EAE8 | 0.055 |
| Achromatopsia (no color) | #CCCCCC | 0.133 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42DEFF
#42DEFF
oklch(83.5% 0.133 215.4)
- #FFB39F
#FFB39F
oklch(83.4% 0.094 35.3)
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 #42DEFF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Aqua Blue #02D8E9 ΔE 0.039
- Robin's Egg #6DEDFD ΔE 0.052
- Bright Sky Blue #02CCFE ΔE 0.055
- Vivid Sky Blue #4CC9F0 ΔE 0.056
- Sky Blue #87CEEB ΔE 0.058
- Light Sky Blue #87CEFA ΔE 0.058
- Lightblue #7BC8F6 ΔE 0.063
- Sky #82CAFC ΔE 0.063
Use #42DEFF 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.