#21AFF3
Closest named color: Deep Sky Blue (#00BFFF). oklch(71.5% 0.148 236.8), rgb(33, 175, 243).
Aa
Black text reads best on this color (8.49:1).
About this color
#21AFF3 is a medium-light, vivid blue. In OKLCH its lightness is 71%, its chroma 0.148 and its hue 237°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.043 away. Black text reads best on it, at 8.49:1.
| Hue family | Blues |
| Lightness | medium-light (71%) |
| Chroma | vivid (0.148) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 8.49:1 |
| White text | 2.47:1 |
Values
| HEX | #21AFF3 |
| RGB | rgb(33, 175, 243) |
| HSL | hsl(199, 90%, 54%) |
| OKLCH | oklch(71.5% 0.148 236.8) |
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 #21AFF3 | 2.47:1 | Fails | Lc -53.1 | Large or bold text, headings |
| Black text on #21AFF3 | 8.49:1 | AAA | Lc 55.9 | Large or bold text, headings |
| #21AFF3 text on white | 2.47:1 | Fails | Lc 48.1 | Large or bold text, headings |
| #21AFF3 text on black | 8.49:1 | AAA | Lc -53.9 | 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
#EEF7FD
oklch(97.1% 0.013 236.6)
-
Step 100
100
#DAEDFA
oklch(93.6% 0.027 237.6)
-
Step 200
200
#BADFF7
oklch(88.5% 0.051 236.6)
-
Step 300
300
#85CAF5
oklch(80.9% 0.093 236.9)
-
Step 400
400 (this color)
#21AFF3
oklch(71.5% 0.148 236.8)
-
Step 500
500
#0094D1
oklch(63.1% 0.137 236.6)
-
Step 600
600
#007CB1
oklch(55.6% 0.122 237.2)
-
Step 700
700
#006895
oklch(49% 0.107 237)
-
Step 800
800
#00557B
oklch(42.6% 0.093 237.2)
-
Step 900
900
#004767
oklch(37.7% 0.082 236.6)
-
Step 950
950
#002A3F
oklch(27% 0.059 236.5)
#21AFF3 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) | #8EAFF6 | 0.084 |
| Deuteranopia (no green cones) | #739DF2 | 0.068 |
| Tritanopia (no blue cones) | #00C0C7 | 0.092 |
| Achromatopsia (no color) | #A5A5A5 | 0.148 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21AFF3
#21AFF3
oklch(71.5% 0.148 236.8)
- #E78837
#E78837
oklch(71.5% 0.148 57)
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 #21AFF3, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.043
- Chefchaouen Blue #4895EF ΔE 0.069
- Turquoise Blue #06B1C4 ΔE 0.074
- Cornflower Blue #6495ED ΔE 0.074
- Bright Sky Blue #02CCFE ΔE 0.078
- Vivid Sky Blue #4CC9F0 ΔE 0.080
- Dark Sky Blue #448EE4 ΔE 0.087
- Carolina Blue #8AB8FE ΔE 0.087
Use #21AFF3 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.