#21B2FF
Closest named color: Deep Sky Blue (#00BFFF). oklch(72.8% 0.158 239.6), rgb(33, 178, 255).
Aa
Black text reads best on this color (8.87:1).
About this color
#21B2FF is a medium-light, vivid blue. In OKLCH its lightness is 73%, its chroma 0.158 and its hue 240°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.035 away. Black text reads best on it, at 8.87:1.
| Hue family | Blues |
| Lightness | medium-light (73%) |
| Chroma | vivid (0.158) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 8.87:1 |
| White text | 2.36:1 |
Values
| HEX | #21B2FF |
| RGB | rgb(33, 178, 255) |
| HSL | hsl(201, 100%, 56%) |
| OKLCH | oklch(72.8% 0.158 239.6) |
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 #21B2FF | 2.36:1 | Fails | Lc -51.0 | Large or bold text, headings |
| Black text on #21B2FF | 8.87:1 | AAA | Lc 57.9 | Large or bold text, headings |
| #21B2FF text on white | 2.36:1 | Fails | Lc 46.1 | Large or bold text, headings |
| #21B2FF text on black | 8.87:1 | AAA | Lc -56.0 | 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
#D9EDFB
oklch(93.6% 0.028 238.2)
-
Step 200
200
#B9DFFA
oklch(88.5% 0.055 239.2)
-
Step 300
300
#83CAFA
oklch(81% 0.099 239.2)
-
Step 400
400 (this color)
#21B2FF
oklch(72.8% 0.158 239.6)
-
Step 500
500
#0093D6
oklch(63.1% 0.143 239.3)
-
Step 600
600
#007BB5
oklch(55.6% 0.127 239.8)
-
Step 700
700
#006799
oklch(49% 0.112 240)
-
Step 800
800
#00557E
oklch(42.8% 0.097 239.2)
-
Step 900
900
#00466A
oklch(37.6% 0.086 240.1)
-
Step 950
950
#002A41
oklch(27.1% 0.061 239)
#21B2FF 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) | #8DB3FF | 0.081 |
| Deuteranopia (no green cones) | #70A0FE | 0.064 |
| Tritanopia (no blue cones) | #00C5CD | 0.103 |
| Achromatopsia (no color) | #A8A8A8 | 0.158 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21B2FF
#21B2FF
oklch(72.8% 0.158 239.6)
- #EE8B28
#EE8B28
oklch(72.8% 0.158 59.4)
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 #21B2FF, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.035
- Bright Sky Blue #02CCFE ΔE 0.072
- Chefchaouen Blue #4895EF ΔE 0.076
- Vivid Sky Blue #4CC9F0 ΔE 0.078
- Cornflower Blue #6495ED ΔE 0.079
- Carolina Blue #8AB8FE ΔE 0.080
- Turquoise Blue #06B1C4 ΔE 0.089
- Dodger Blue #1E90FF ΔE 0.092
Use #21B2FF 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.