#21BCDF
Closest named color: Deep Sky Blue (#00BFFF). oklch(73.6% 0.127 218.4), rgb(33, 188, 223).
Aa
Black text reads best on this color (9.32:1).
About this color
#21BCDF is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 74%, its chroma 0.127 and its hue 218°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.046 away. Black text reads best on it, at 9.32:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (74%) |
| Chroma | moderately saturated (0.127) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.32:1 |
| White text | 2.25:1 |
Values
| HEX | #21BCDF |
| RGB | rgb(33, 188, 223) |
| HSL | hsl(191, 75%, 50%) |
| OKLCH | oklch(73.6% 0.127 218.4) |
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 #21BCDF | 2.25:1 | Fails | Lc -48.7 | Large or bold text, headings |
| Black text on #21BCDF | 9.32:1 | AAA | Lc 60.1 | Content text, not long reading |
| #21BCDF text on white | 2.25:1 | Fails | Lc 43.9 | Non-text elements, placeholder text |
| #21BCDF text on black | 9.32:1 | AAA | Lc -58.3 | Large or bold text, headings |
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
#EEF7FA
oklch(97% 0.01 219.6)
-
Step 100
100
#DAEEF4
oklch(93.6% 0.023 217.6)
-
Step 200
200
#BAE1ED
oklch(88.6% 0.044 218.4)
-
Step 300
300
#84CDE3
oklch(80.8% 0.079 218.9)
-
Step 400
400 (this color)
#21BCDF
oklch(73.6% 0.127 218.4)
-
Step 500
500
#0099B7
oklch(63.1% 0.114 218.3)
-
Step 600
600
#00819A
oklch(55.7% 0.1 217.7)
-
Step 700
700
#006C82
oklch(49.1% 0.088 218.4)
-
Step 800
800
#00596B
oklch(42.8% 0.077 217.7)
-
Step 900
900
#004A5A
oklch(37.8% 0.068 218.5)
-
Step 950
950
#002C36
oklch(27% 0.048 217.4)
#21BCDF 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) | #A6B6E1 | 0.108 |
| Deuteranopia (no green cones) | #8EA5DF | 0.097 |
| Tritanopia (no blue cones) | #00C8C7 | 0.057 |
| Achromatopsia (no color) | #ADADAD | 0.128 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21BCDF
#21BCDF
oklch(73.6% 0.127 218.4)
- #ED8C6D
#ED8C6D
oklch(73.6% 0.126 38.5)
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 #21BCDF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.046
- Turquoise Blue #06B1C4 ΔE 0.046
- Vivid Sky Blue #4CC9F0 ΔE 0.047
- Bright Sky Blue #02CCFE ΔE 0.054
- Dark Turquoise #00CED1 ΔE 0.061
- Topaz #13BBAF ΔE 0.072
- Aqua Blue #02D8E9 ΔE 0.076
- Medium Turquoise #48D1CC ΔE 0.077
Use #21BCDF 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.