#42DEF5
Closest named color: Aqua Blue (#02D8E9). oklch(83.1% 0.129 209.5), rgb(66, 222, 245).
Aa
Black text reads best on this color (12.99:1).
About this color
#42DEF5 is a light, moderately saturated teal or cyan. In OKLCH its lightness is 83%, its chroma 0.129 and its hue 210°. Its hue sits on the cool side of the wheel. The nearest named color is Aqua Blue (#02D8E9), ΔE 0.029 away. Black text reads best on it, at 12.99:1.
| Hue family | Teals and cyans |
| Lightness | light (83%) |
| Chroma | moderately saturated (0.129) |
| Temperature | cool |
| Nearest name | Aqua Blue (#02D8E9) |
| Black text | 12.99:1 |
| White text | 1.61:1 |
Values
| HEX | #42DEF5 |
| RGB | rgb(66, 222, 245) |
| HSL | hsl(188, 90%, 61%) |
| OKLCH | oklch(83.1% 0.129 209.5) |
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 #42DEF5 | 1.61:1 | Fails | Lc -30.7 | Non-text elements, placeholder text |
| Black text on #42DEF5 | 12.99:1 | AAA | Lc 76.6 | Fine for body text |
| #42DEF5 text on white | 1.61:1 | Fails | Lc 27.2 | Dividers and decoration only |
| #42DEF5 text on black | 12.99:1 | AAA | Lc -75.8 | 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
#E9F9FC
oklch(97.1% 0.017 210.2)
-
Step 100
100
#CEF1F8
oklch(93.5% 0.038 211.1)
-
Step 200
200
#A1E7F3
oklch(88.6% 0.071 209.3)
-
Step 300
300 (this color)
#42DEF5
oklch(83.1% 0.129 209.5)
-
Step 400
400
#00B5CA
oklch(70.8% 0.122 209.4)
-
Step 500
500
#009BAD
oklch(63.1% 0.109 209.2)
-
Step 600
600
#008292
oklch(55.6% 0.096 209.8)
-
Step 700
700
#006D7B
oklch(49% 0.085 210.2)
-
Step 800
800
#005A65
oklch(42.8% 0.074 209.1)
-
Step 900
900
#004B54
oklch(37.8% 0.065 208.5)
-
Step 950
950
#002C33
oklch(26.9% 0.047 211.1)
#42DEF5 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) | #CAD6F6 | 0.122 |
| Deuteranopia (no green cones) | #B1C4F5 | 0.110 |
| Tritanopia (no blue cones) | #00E8E5 | 0.043 |
| Achromatopsia (no color) | #CBCBCB | 0.129 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42DEF5
#42DEF5
oklch(83.1% 0.129 209.5)
- #FFB1A4
#FFB1A4
oklch(83.1% 0.094 29.7)
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 #42DEF5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Aqua Blue #02D8E9 ΔE 0.029
- Robin's Egg #6DEDFD ΔE 0.051
- Turquoise #40E0D0 ΔE 0.056
- Vivid Sky Blue #4CC9F0 ΔE 0.056
- Sky Blue #87CEEB ΔE 0.057
- Medium Turquoise #48D1CC ΔE 0.060
- Bright Sky Blue #02CCFE ΔE 0.060
- Light Sky Blue #87CEFA ΔE 0.063
Use #42DEF5 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.