#21B0FF
Closest named color: Deep Sky Blue (#00BFFF). oklch(72.3% 0.16 240.6), rgb(33, 176, 255).
Aa
Black text reads best on this color (8.71:1).
About this color
#21B0FF is a medium-light, vivid blue. In OKLCH its lightness is 72%, its chroma 0.160 and its hue 241°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.041 away. Black text reads best on it, at 8.71:1.
| Hue family | Blues |
| Lightness | medium-light (72%) |
| Chroma | vivid (0.160) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 8.71:1 |
| White text | 2.40:1 |
Values
| HEX | #21B0FF |
| RGB | rgb(33, 176, 255) |
| HSL | hsl(201, 100%, 56%) |
| OKLCH | oklch(72.3% 0.16 240.6) |
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 #21B0FF | 2.40:1 | Fails | Lc -51.8 | Large or bold text, headings |
| Black text on #21B0FF | 8.71:1 | AAA | Lc 57.1 | Large or bold text, headings |
| #21B0FF text on white | 2.40:1 | Fails | Lc 46.9 | Large or bold text, headings |
| #21B0FF text on black | 8.71:1 | AAA | Lc -55.2 | 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
#EEF7FE
oklch(97.1% 0.013 241)
-
Step 100
100
#D9EDFC
oklch(93.6% 0.029 240.2)
-
Step 200
200
#B9DFFB
oklch(88.6% 0.056 240.2)
-
Step 300
300
#83C9FB
oklch(80.8% 0.1 240.7)
-
Step 400
400 (this color)
#21B0FF
oklch(72.3% 0.16 240.6)
-
Step 500
500
#0092D8
oklch(63% 0.146 240.6)
-
Step 600
600
#007BB7
oklch(55.7% 0.129 240.7)
-
Step 700
700
#00679A
oklch(49.1% 0.113 240.5)
-
Step 800
800
#00547F
oklch(42.6% 0.099 240.7)
-
Step 900
900
#00466B
oklch(37.7% 0.087 240.8)
-
Step 950
950
#002942
oklch(26.9% 0.063 241.6)
#21B0FF 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) | #8AB1FF | 0.078 |
| Deuteranopia (no green cones) | #6C9EFE | 0.062 |
| Tritanopia (no blue cones) | #00C4CC | 0.106 |
| Achromatopsia (no color) | #A7A7A7 | 0.160 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21B0FF
#21B0FF
oklch(72.3% 0.16 240.6)
- #EC8A20
#EC8A20
oklch(72.3% 0.16 60.6)
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 #21B0FF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.041
- Chefchaouen Blue #4895EF ΔE 0.070
- Cornflower Blue #6495ED ΔE 0.075
- Bright Sky Blue #02CCFE ΔE 0.077
- Vivid Sky Blue #4CC9F0 ΔE 0.083
- Carolina Blue #8AB8FE ΔE 0.083
- Dodger Blue #1E90FF ΔE 0.087
- Turquoise Blue #06B1C4 ΔE 0.091
Use #21B0FF 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.