#21B7ED
Closest named color: Deep Sky Blue (#00BFFF). oklch(73.1% 0.138 229.4), rgb(33, 183, 237).
Aa
Black text reads best on this color (9.06:1).
About this color
#21B7ED is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 73%, its chroma 0.138 and its hue 229°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.030 away. Black text reads best on it, at 9.06:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (73%) |
| Chroma | moderately saturated (0.138) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.06:1 |
| White text | 2.31:1 |
Values
| HEX | #21B7ED |
| RGB | rgb(33, 183, 237) |
| HSL | hsl(196, 85%, 53%) |
| OKLCH | oklch(73.1% 0.138 229.4) |
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 #21B7ED | 2.31:1 | Fails | Lc -50.0 | Large or bold text, headings |
| Black text on #21B7ED | 9.06:1 | AAA | Lc 58.8 | Large or bold text, headings |
| #21B7ED text on white | 2.31:1 | Fails | Lc 45.2 | Large or bold text, headings |
| #21B7ED text on black | 9.06:1 | AAA | Lc -56.9 | 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
#EEF7FC
oklch(97.1% 0.012 231.7)
-
Step 100
100
#DAEEF8
oklch(93.7% 0.025 229.1)
-
Step 200
200
#BAE0F3
oklch(88.6% 0.048 229.6)
-
Step 300
300
#84CCEE
oklch(81% 0.087 229.5)
-
Step 400
400 (this color)
#21B7ED
oklch(73.1% 0.138 229.4)
-
Step 500
500
#0096C6
oklch(63% 0.126 229.9)
-
Step 600
600
#007EA7
oklch(55.5% 0.111 230)
-
Step 700
700
#006A8D
oklch(49.1% 0.098 229.8)
-
Step 800
800
#005774
oklch(42.7% 0.085 229.4)
-
Step 900
900
#004861
oklch(37.6% 0.075 229.8)
-
Step 950
950
#002B3B
oklch(27% 0.053 228.8)
#21B7ED 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) | #9BB4F0 | 0.096 |
| Deuteranopia (no green cones) | #81A2EC | 0.082 |
| Tritanopia (no blue cones) | #00C6C9 | 0.078 |
| Achromatopsia (no color) | #AAAAAA | 0.139 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21B7ED
#21B7ED
oklch(73.1% 0.138 229.4)
- #EC8B53
#EC8B53
oklch(72.9% 0.138 49.3)
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 #21B7ED, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.030
- Vivid Sky Blue #4CC9F0 ΔE 0.057
- Bright Sky Blue #02CCFE ΔE 0.057
- Turquoise Blue #06B1C4 ΔE 0.061
- Lightblue #7BC8F6 ΔE 0.080
- Carolina Blue #8AB8FE ΔE 0.082
- Dark Turquoise #00CED1 ΔE 0.087
- Sky #82CAFC ΔE 0.091
Use #21B7ED 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.