#21C4FC
Closest named color: Deep Sky Blue (#00BFFF). oklch(76.8% 0.145 228.5), rgb(33, 196, 252).
Aa
Black text reads best on this color (10.36:1).
About this color
#21C4FC is a medium-light, vivid teal or cyan. In OKLCH its lightness is 77%, its chroma 0.145 and its hue 229°. Its hue sits on the cool side of the wheel. The nearest named color is Deep Sky Blue (#00BFFF), ΔE 0.017 away. Black text reads best on it, at 10.36:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (77%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Deep Sky Blue (#00BFFF) |
| Black text | 10.36:1 |
| White text | 2.02:1 |
Values
| HEX | #21C4FC |
| RGB | rgb(33, 196, 252) |
| HSL | hsl(195, 97%, 56%) |
| OKLCH | oklch(76.8% 0.145 228.5) |
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 #21C4FC | 2.02:1 | Fails | Lc -43.3 | Non-text elements, placeholder text |
| Black text on #21C4FC | 10.36:1 | AAA | Lc 65.1 | Content text, not long reading |
| #21C4FC text on white | 2.02:1 | Fails | Lc 38.8 | Non-text elements, placeholder text |
| #21C4FC text on black | 10.36:1 | AAA | Lc -63.6 | Content text, not long reading |
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 300.
-
Step 50
50
#EAF8FF
oklch(97.1% 0.018 229)
-
Step 100
100
#D0F0FF
oklch(93.7% 0.039 227.7)
-
Step 200
200
#A7E3FF
oklch(88.5% 0.072 228.5)
-
Step 300
300 (this color)
#21C4FC
oklch(76.8% 0.145 228.5)
-
Step 400
400
#00B0E4
oklch(70.7% 0.138 228.2)
-
Step 500
500
#0097C4
oklch(63.2% 0.123 228.1)
-
Step 600
600
#007FA6
oklch(55.7% 0.109 228.5)
-
Step 700
700
#006A8C
oklch(49% 0.097 229.1)
-
Step 800
800
#005773
oklch(42.7% 0.084 228.5)
-
Step 900
900
#004860
oklch(37.5% 0.074 228.7)
-
Step 950
950
#002B3B
oklch(27% 0.053 228.8)
#21C4FC 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) | #A7C1FF | 0.103 |
| Deuteranopia (no green cones) | #8BAEFB | 0.087 |
| Tritanopia (no blue cones) | #00D4D7 | 0.080 |
| Achromatopsia (no color) | #B6B6B6 | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #21C4FC
#21C4FC
oklch(76.8% 0.145 228.5)
- #FD955B
#FD955B
oklch(76.8% 0.145 48.6)
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 #21C4FC, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Deep Sky Blue #00BFFF ΔE 0.017
- Bright Sky Blue #02CCFE ΔE 0.021
- Vivid Sky Blue #4CC9F0 ΔE 0.031
- Lightblue #7BC8F6 ΔE 0.057
- Sky #82CAFC ΔE 0.066
- Aqua Blue #02D8E9 ΔE 0.069
- Carolina Blue #8AB8FE ΔE 0.074
- Light Sky Blue #87CEFA ΔE 0.075
Use #21C4FC 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.