#21D4DC
Closest named color: Aqua Blue (#02D8E9). oklch(79.3% 0.13 199.9), rgb(33, 212, 220).
Aa
Black text reads best on this color (11.51:1).
About this color
#21D4DC is a light, moderately saturated teal or cyan. In OKLCH its lightness is 79%, its chroma 0.130 and its hue 200°. Its hue sits on the cool side of the wheel. The nearest named color is Aqua Blue (#02D8E9), ΔE 0.018 away. Black text reads best on it, at 11.51:1.
| Hue family | Teals and cyans |
| Lightness | light (79%) |
| Chroma | moderately saturated (0.130) |
| Temperature | cool |
| Nearest name | Aqua Blue (#02D8E9) |
| Black text | 11.51:1 |
| White text | 1.82:1 |
Values
| HEX | #21D4DC |
| RGB | rgb(33, 212, 220) |
| HSL | hsl(183, 74%, 50%) |
| OKLCH | oklch(79.3% 0.13 199.9) |
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 #21D4DC | 1.82:1 | Fails | Lc -37.6 | Non-text elements, placeholder text |
| Black text on #21D4DC | 11.51:1 | AAA | Lc 70.3 | Content text, not long reading |
| #21D4DC text on white | 1.82:1 | Fails | Lc 33.5 | Non-text elements, placeholder text |
| #21D4DC text on black | 11.51:1 | AAA | Lc -69.1 | 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
#E9F9FA
oklch(97.1% 0.017 201.4)
-
Step 100
100
#CEF2F4
oklch(93.6% 0.037 200.7)
-
Step 200
200
#9FE8EC
oklch(88.5% 0.072 200.3)
-
Step 300
300 (this color)
#21D4DC
oklch(79.3% 0.13 199.9)
-
Step 400
400
#00B7BE
oklch(70.8% 0.12 199.7)
-
Step 500
500
#009CA3
oklch(63% 0.107 200.4)
-
Step 600
600
#008489
oklch(55.7% 0.095 199.5)
-
Step 700
700
#006F73
oklch(49.2% 0.084 199.2)
-
Step 800
800
#005B5E
oklch(42.8% 0.073 198.7)
-
Step 900
900
#004C4F
oklch(37.8% 0.064 199.4)
-
Step 950
950
#002D2F
oklch(27% 0.046 199.4)
#21D4DC 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) | #C3CADD | 0.132 |
| Deuteranopia (no green cones) | #ABB8DD | 0.123 |
| Tritanopia (no blue cones) | #00DCD6 | 0.027 |
| Achromatopsia (no color) | #C0C0C0 | 0.131 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21D4DC
#21D4DC
oklch(79.3% 0.13 199.9)
- #FF9B9C
#FF9B9C
oklch(79.2% 0.12 19.5)
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 #21D4DC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Aqua Blue #02D8E9 ΔE 0.018
- Dark Turquoise #00CED1 ΔE 0.022
- Medium Turquoise #48D1CC ΔE 0.023
- Turquoise #40E0D0 ΔE 0.045
- Vivid Sky Blue #4CC9F0 ΔE 0.051
- Bright Sky Blue #02CCFE ΔE 0.060
- Seafoam Blue #78D1B6 ΔE 0.064
- Medium Aquamarine #66CDAA ΔE 0.069
Use #21D4DC 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.