#42E9FF
Closest named color: Robin's Egg (#6DEDFD). oklch(86% 0.134 208.2), rgb(66, 233, 255).
Aa
Black text reads best on this color (14.33:1).
About this color
#42E9FF is a light, moderately saturated teal or cyan. In OKLCH its lightness is 86%, its chroma 0.134 and its hue 208°. Its hue sits on the cool side of the wheel. The nearest named color is Robin's Egg (#6DEDFD), ΔE 0.028 away. Black text reads best on it, at 14.33:1.
| Hue family | Teals and cyans |
| Lightness | light (86%) |
| Chroma | moderately saturated (0.134) |
| Temperature | cool |
| Nearest name | Robin's Egg (#6DEDFD) |
| Black text | 14.33:1 |
| White text | 1.46:1 |
Values
| HEX | #42E9FF |
| RGB | rgb(66, 233, 255) |
| HSL | hsl(187, 100%, 63%) |
| OKLCH | oklch(86% 0.134 208.2) |
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 #42E9FF | 1.46:1 | Fails | Lc -24.6 | Dividers and decoration only |
| Black text on #42E9FF | 14.33:1 | AAA | Lc 82.1 | Fine for body text |
| #42E9FF text on white | 1.46:1 | Fails | Lc 21.6 | Dividers and decoration only |
| #42E9FF text on black | 14.33:1 | AAA | Lc -81.7 | 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 200.
-
Step 50
50
#E5FAFE
oklch(97.1% 0.023 210.4)
-
Step 100
100
#C4F4FB
oklch(93.6% 0.05 207.3)
-
Step 200
200 (this color)
#42E9FF
oklch(86% 0.134 208.2)
-
Step 300
300
#00D9EF
oklch(81% 0.139 207.7)
-
Step 400
400
#00B5C8
oklch(70.7% 0.122 208)
-
Step 500
500
#009BAC
oklch(63.1% 0.109 208.4)
-
Step 600
600
#008291
oklch(55.5% 0.096 208.9)
-
Step 700
700
#006E7A
oklch(49.2% 0.085 207.9)
-
Step 800
800
#005A64
oklch(42.8% 0.073 207.9)
-
Step 900
900
#004B54
oklch(37.8% 0.065 208.5)
-
Step 950
950
#002C32
oklch(26.8% 0.046 208.8)
#42E9FF 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) | #D4E0FF | 0.128 |
| Deuteranopia (no green cones) | #BACDFF | 0.117 |
| Tritanopia (no blue cones) | #00F4F0 | 0.044 |
| Achromatopsia (no color) | #D5D5D5 | 0.135 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42E9FF
#42E9FF
oklch(86% 0.134 208.2)
- #FFBFB5
#FFBFB5
oklch(86% 0.076 28.8)
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 #42E9FF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Robin's Egg #6DEDFD ΔE 0.028
- Bright Light Blue #26F7FD ΔE 0.039
- Robin Egg Blue #8AF1FE ΔE 0.054
- Aqua Blue #02D8E9 ΔE 0.056
- Bright Cyan #41FDFE ΔE 0.056
- Cyan #00FFFF ΔE 0.060
- Bright Turquoise #0FFEF9 ΔE 0.061
- Bright Aqua #0BF9EA ΔE 0.061
Use #42E9FF 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.