#21D8FA
Closest named color: Aqua Blue (#02D8E9). oklch(81.4% 0.139 215.1), rgb(33, 216, 250).
Aa
Black text reads best on this color (12.26:1).
About this color
#21D8FA is a light, moderately saturated teal or cyan. In OKLCH its lightness is 81%, its chroma 0.139 and its hue 215°. Its hue sits on the cool side of the wheel. The nearest named color is Aqua Blue (#02D8E9), ΔE 0.026 away. Black text reads best on it, at 12.26:1.
| Hue family | Teals and cyans |
| Lightness | light (81%) |
| Chroma | moderately saturated (0.139) |
| Temperature | cool |
| Nearest name | Aqua Blue (#02D8E9) |
| Black text | 12.26:1 |
| White text | 1.71:1 |
Values
| HEX | #21D8FA |
| RGB | rgb(33, 216, 250) |
| HSL | hsl(189, 96%, 55%) |
| OKLCH | oklch(81.4% 0.139 215.1) |
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 #21D8FA | 1.71:1 | Fails | Lc -34.0 | Non-text elements, placeholder text |
| Black text on #21D8FA | 12.26:1 | AAA | Lc 73.7 | Content text, not long reading |
| #21D8FA text on white | 1.71:1 | Fails | Lc 30.2 | Non-text elements, placeholder text |
| #21D8FA text on black | 12.26:1 | AAA | Lc -72.6 | 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
#E8F9FD
oklch(97.1% 0.019 213.4)
-
Step 100
100
#CDF1FB
oklch(93.6% 0.04 216.4)
-
Step 200
200
#9DE7F9
oklch(88.6% 0.077 214.7)
-
Step 300
300 (this color)
#21D8FA
oklch(81.4% 0.139 215.1)
-
Step 400
400
#00B3D1
oklch(70.6% 0.125 215.4)
-
Step 500
500
#009AB3
oklch(63.1% 0.111 214.6)
-
Step 600
600
#008197
oklch(55.5% 0.098 215.2)
-
Step 700
700
#006D7F
oklch(49.2% 0.087 214.3)
-
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)
#21D8FA 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) | #C0D1FC | 0.123 |
| Deuteranopia (no green cones) | #A5BDFA | 0.112 |
| Tritanopia (no blue cones) | #00E4E3 | 0.054 |
| Achromatopsia (no color) | #C6C6C6 | 0.140 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21D8FA
#21D8FA
oklch(81.4% 0.139 215.1)
- #FFA993
#FFA993
oklch(81.4% 0.107 35)
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 #21D8FA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Aqua Blue #02D8E9 ΔE 0.026
- Bright Sky Blue #02CCFE ΔE 0.037
- Vivid Sky Blue #4CC9F0 ΔE 0.040
- Lightblue #7BC8F6 ΔE 0.060
- Dark Turquoise #00CED1 ΔE 0.061
- Sky Blue #87CEEB ΔE 0.061
- Light Sky Blue #87CEFA ΔE 0.063
- Medium Turquoise #48D1CC ΔE 0.063
Use #21D8FA 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.