#21BCF5
Closest named color: Deep Sky Blue (#00BFFF). oklch(74.6% 0.143 230.1), rgb(33, 188, 245).
Aa
Black text reads best on this color (9.57:1).
About this color
#21BCF5 is a medium-light, vivid blue. In OKLCH its lightness is 75%, its chroma 0.143 and its hue 230°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.015 away. Black text reads best on it, at 9.57:1.
| Hue family | Blues |
| Lightness | medium-light (75%) |
| Chroma | vivid (0.143) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 9.57:1 |
| White text | 2.19:1 |
Values
| HEX | #21BCF5 |
| RGB | rgb(33, 188, 245) |
| HSL | hsl(196, 91%, 55%) |
| OKLCH | oklch(74.6% 0.143 230.1) |
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 #21BCF5 | 2.19:1 | Fails | Lc -47.3 | Large or bold text, headings |
| Black text on #21BCF5 | 9.57:1 | AAA | Lc 61.4 | Content text, not long reading |
| #21BCF5 text on white | 2.19:1 | Fails | Lc 42.6 | Non-text elements, placeholder text |
| #21BCF5 text on black | 9.57:1 | AAA | Lc -59.6 | 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
#D9EEF8
oklch(93.7% 0.026 227.9)
-
Step 200
200
#B9E0F4
oklch(88.5% 0.049 230.3)
-
Step 300
300
#82CCEF
oklch(80.9% 0.089 229.6)
-
Step 400
400 (this color)
#21BCF5
oklch(74.6% 0.143 230.1)
-
Step 500
500
#0096C7
oklch(63.1% 0.126 230.5)
-
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
#004862
oklch(37.7% 0.076 230.8)
-
Step 950
950
#002B3C
oklch(27.1% 0.054 230.4)
#21BCF5 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) | #9FB9F8 | 0.098 |
| Deuteranopia (no green cones) | #84A7F4 | 0.083 |
| Tritanopia (no blue cones) | #00CCCF | 0.082 |
| Achromatopsia (no color) | #AFAFAF | 0.143 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21BCF5
#21BCF5
oklch(74.6% 0.143 230.1)
- #F38F53
#F38F53
oklch(74.5% 0.143 50.1)
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 #21BCF5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.015
- Bright Sky Blue #02CCFE ΔE 0.042
- Vivid Sky Blue #4CC9F0 ΔE 0.046
- Lightblue #7BC8F6 ΔE 0.070
- Turquoise Blue #06B1C4 ΔE 0.074
- Carolina Blue #8AB8FE ΔE 0.076
- Sky #82CAFC ΔE 0.079
- Dark Turquoise #00CED1 ΔE 0.084
Use #21BCF5 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.