#21ABE9
Closest named color: Deep Sky Blue (#00BFFF). oklch(70.1% 0.141 234.9), rgb(33, 171, 233).
Aa
Black text reads best on this color (8.06:1).
About this color
#21ABE9 is a medium-light, vivid blue. In OKLCH its lightness is 70%, its chroma 0.141 and its hue 235°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.057 away. Black text reads best on it, at 8.06:1.
| Hue family | Blues |
| Lightness | medium-light (70%) |
| Chroma | vivid (0.141) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 8.06:1 |
| White text | 2.60:1 |
Values
| HEX | #21ABE9 |
| RGB | rgb(33, 171, 233) |
| HSL | hsl(199, 82%, 52%) |
| OKLCH | oklch(70.1% 0.141 234.9) |
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 #21ABE9 | 2.60:1 | Fails | Lc -55.4 | Large or bold text, headings |
| Black text on #21ABE9 | 8.06:1 | AAA | Lc 53.7 | Large or bold text, headings |
| #21ABE9 text on white | 2.60:1 | Fails | Lc 50.3 | Large or bold text, headings |
| #21ABE9 text on black | 8.06:1 | AAA | Lc -51.6 | 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
#DAEDF9
oklch(93.6% 0.026 235.4)
-
Step 200
200
#BBDFF5
oklch(88.5% 0.049 234.9)
-
Step 300
300
#87CAF2
oklch(80.9% 0.088 235.6)
-
Step 400
400 (this color)
#21ABE9
oklch(70.1% 0.141 234.9)
-
Step 500
500
#0095CE
oklch(63.2% 0.133 234.7)
-
Step 600
600
#007DAE
oklch(55.7% 0.118 234.9)
-
Step 700
700
#006993
oklch(49.2% 0.104 234.9)
-
Step 800
800
#005679
oklch(42.8% 0.09 234.7)
-
Step 900
900
#004766
oklch(37.6% 0.081 235.8)
-
Step 950
950
#002A3E
oklch(26.9% 0.057 235.2)
#21ABE9 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) | #8CAAEC | 0.084 |
| Deuteranopia (no green cones) | #7399E8 | 0.069 |
| Tritanopia (no blue cones) | #00BBC0 | 0.087 |
| Achromatopsia (no color) | #A0A0A0 | 0.141 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21ABE9
#21ABE9
oklch(70.1% 0.141 234.9)
- #E0843E
#E0843E
oklch(70% 0.141 54.9)
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 #21ABE9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.057
- Chefchaouen Blue #4895EF ΔE 0.063
- Turquoise Blue #06B1C4 ΔE 0.064
- Cornflower Blue #6495ED ΔE 0.070
- Dark Sky Blue #448EE4 ΔE 0.077
- Dodger Blue #1E90FF ΔE 0.086
- Greyblue #77A1B5 ΔE 0.089
- Vivid Sky Blue #4CC9F0 ΔE 0.089
Use #21ABE9 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.