#42D3EB
Closest named color: Aqua Blue (#02D8E9). oklch(80.1% 0.123 211.1), rgb(66, 211, 235).
Aa
Black text reads best on this color (11.74:1).
About this color
#42D3EB is a light, moderately saturated teal or cyan. In OKLCH its lightness is 80%, its chroma 0.123 and its hue 211°. Its hue sits on the cool side of the wheel. The nearest named color is Aqua Blue (#02D8E9), ΔE 0.020 away. Black text reads best on it, at 11.74:1.
| Hue family | Teals and cyans |
| Lightness | light (80%) |
| Chroma | moderately saturated (0.123) |
| Temperature | cool |
| Nearest name | Aqua Blue (#02D8E9) |
| Black text | 11.74:1 |
| White text | 1.78:1 |
Values
| HEX | #42D3EB |
| RGB | rgb(66, 211, 235) |
| HSL | hsl(189, 81%, 59%) |
| OKLCH | oklch(80.1% 0.123 211.1) |
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 #42D3EB | 1.78:1 | Fails | Lc -36.6 | Non-text elements, placeholder text |
| Black text on #42D3EB | 11.74:1 | AAA | Lc 71.2 | Content text, not long reading |
| #42D3EB text on white | 1.78:1 | Fails | Lc 32.6 | Non-text elements, placeholder text |
| #42D3EB text on black | 11.74:1 | AAA | Lc -70.0 | 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
#EAF9FC
oklch(97.2% 0.016 211)
-
Step 100
100
#D0F1F7
oklch(93.6% 0.035 209.8)
-
Step 200
200
#A4E6F3
oklch(88.5% 0.068 211.2)
-
Step 300
300 (this color)
#42D3EB
oklch(80.1% 0.123 211.1)
-
Step 400
400
#00B4CC
oklch(70.6% 0.123 211.4)
-
Step 500
500
#009BAF
oklch(63.2% 0.11 210.8)
-
Step 600
600
#008293
oklch(55.6% 0.096 210.7)
-
Step 700
700
#006D7C
oklch(49% 0.085 211.2)
-
Step 800
800
#005966
oklch(42.6% 0.074 211.8)
-
Step 900
900
#004B55
oklch(37.8% 0.065 210)
-
Step 950
950
#002C33
oklch(26.9% 0.047 211.1)
#42D3EB 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) | #BFCCEC | 0.114 |
| Deuteranopia (no green cones) | #A8BAEB | 0.105 |
| Tritanopia (no blue cones) | #00DDDA | 0.045 |
| Achromatopsia (no color) | #C2C2C2 | 0.124 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42D3EB
#42D3EB
oklch(80.1% 0.123 211.1)
- #FFA291
#FFA291
oklch(80.2% 0.114 31)
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 #42D3EB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Aqua Blue #02D8E9 ΔE 0.020
- Vivid Sky Blue #4CC9F0 ΔE 0.031
- Bright Sky Blue #02CCFE ΔE 0.041
- Medium Turquoise #48D1CC ΔE 0.044
- Dark Turquoise #00CED1 ΔE 0.044
- Sky Blue #87CEEB ΔE 0.051
- Lightblue #7BC8F6 ΔE 0.053
- Light Sky Blue #87CEFA ΔE 0.059
Use #42D3EB 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.