#21C4DA
Closest named color: Dark Turquoise (#00CED1). oklch(75.3% 0.125 209.6), rgb(33, 196, 218).
Aa
Black text reads best on this color (9.97:1).
About this color
#21C4DA is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 75%, its chroma 0.125 and its hue 210°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Turquoise (#00CED1), ΔE 0.035 away. Black text reads best on it, at 9.97:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (75%) |
| Chroma | moderately saturated (0.125) |
| Temperature | cool |
| Nearest name | Dark Turquoise (#00CED1) |
| Black text | 9.97:1 |
| White text | 2.10:1 |
Values
| HEX | #21C4DA |
| RGB | rgb(33, 196, 218) |
| HSL | hsl(187, 74%, 49%) |
| OKLCH | oklch(75.3% 0.125 209.6) |
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 #21C4DA | 2.10:1 | Fails | Lc -45.3 | Large or bold text, headings |
| Black text on #21C4DA | 9.97:1 | AAA | Lc 63.2 | Content text, not long reading |
| #21C4DA text on white | 2.10:1 | Fails | Lc 40.7 | Non-text elements, placeholder text |
| #21C4DA text on black | 9.97:1 | AAA | Lc -61.6 | 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 400.
-
Step 50
50
#EEF8F9
oklch(97.2% 0.011 204.1)
-
Step 100
100
#DAEEF2
oklch(93.6% 0.022 211)
-
Step 200
200
#B9E2E9
oklch(88.6% 0.044 209.1)
-
Step 300
300
#82CFDC
oklch(80.9% 0.078 209.3)
-
Step 400
400 (this color)
#21C4DA
oklch(75.3% 0.125 209.6)
-
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)
#21C4DA 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) | #B1BCDB | 0.118 |
| Deuteranopia (no green cones) | #9AABDA | 0.108 |
| Tritanopia (no blue cones) | #00CECB | 0.041 |
| Achromatopsia (no color) | #B3B3B3 | 0.126 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21C4DA
#21C4DA
oklch(75.3% 0.125 209.6)
- #F48F80
#F48F80
oklch(75.3% 0.125 29.3)
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 #21C4DA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Turquoise #00CED1 ΔE 0.035
- Vivid Sky Blue #4CC9F0 ΔE 0.040
- Medium Turquoise #48D1CC ΔE 0.051
- Bright Sky Blue #02CCFE ΔE 0.051
- Aqua Blue #02D8E9 ΔE 0.054
- Turquoise Blue #06B1C4 ΔE 0.058
- Deep Sky Blue #00BFFF ΔE 0.060
- Topaz #13BBAF ΔE 0.063
Use #21C4DA 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.