#21B7EB
Closest named color: Deep Sky Blue (#00BFFF). oklch(73% 0.137 228.4), rgb(33, 183, 235).
Aa
Black text reads best on this color (9.03:1).
About this color
#21B7EB is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 73%, its chroma 0.137 and its hue 228°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.032 away. Black text reads best on it, at 9.03:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (73%) |
| Chroma | moderately saturated (0.137) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.03:1 |
| White text | 2.32:1 |
Values
| HEX | #21B7EB |
| RGB | rgb(33, 183, 235) |
| HSL | hsl(195, 83%, 53%) |
| OKLCH | oklch(73% 0.137 228.4) |
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 #21B7EB | 2.32:1 | Fails | Lc -50.2 | Large or bold text, headings |
| Black text on #21B7EB | 9.03:1 | AAA | Lc 58.7 | Large or bold text, headings |
| #21B7EB text on white | 2.32:1 | Fails | Lc 45.3 | Large or bold text, headings |
| #21B7EB text on black | 9.03:1 | AAA | Lc -56.8 | 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
#DAEEF7
oklch(93.7% 0.024 226.5)
-
Step 200
200
#BAE0F2
oklch(88.5% 0.047 228.2)
-
Step 300
300
#84CCEC
oklch(80.9% 0.085 227.9)
-
Step 400
400 (this color)
#21B7EB
oklch(73% 0.137 228.4)
-
Step 500
500
#0097C4
oklch(63.2% 0.123 228.1)
-
Step 600
600
#007FA5
oklch(55.7% 0.108 227.8)
-
Step 700
700
#006A8C
oklch(49% 0.097 229.1)
-
Step 800
800
#005773
oklch(42.7% 0.084 228.5)
-
Step 900
900
#004860
oklch(37.5% 0.074 228.7)
-
Step 950
950
#002B3B
oklch(27% 0.053 228.8)
#21B7EB 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) | #9CB4EE | 0.098 |
| Deuteranopia (no green cones) | #82A2EA | 0.083 |
| Tritanopia (no blue cones) | #00C6C8 | 0.077 |
| Achromatopsia (no color) | #AAAAAA | 0.137 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21B7EB
#21B7EB
oklch(73% 0.137 228.4)
- #EC8B56
#EC8B56
oklch(73% 0.137 48.2)
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 #21B7EB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.032
- Vivid Sky Blue #4CC9F0 ΔE 0.057
- Bright Sky Blue #02CCFE ΔE 0.058
- Turquoise Blue #06B1C4 ΔE 0.058
- Lightblue #7BC8F6 ΔE 0.081
- Carolina Blue #8AB8FE ΔE 0.084
- Dark Turquoise #00CED1 ΔE 0.085
- Sky #82CAFC ΔE 0.091
Use #21B7EB 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.