#66C4E1
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(77.4% 0.098 220.5), rgb(102, 196, 225).
Aa
Black text reads best on this color (10.54:1).
About this color
#66C4E1 is a medium-light, moderately saturated teal or cyan. In OKLCH its lightness is 77%, its chroma 0.098 and its hue 220°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.025 away. Black text reads best on it, at 10.54:1.
| Hue family | Teals and cyans |
| Lightness | medium-light (77%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 10.54:1 |
| White text | 1.99:1 |
Values
| HEX | #66C4E1 |
| RGB | rgb(102, 196, 225) |
| HSL | hsl(194, 67%, 64%) |
| OKLCH | oklch(77.4% 0.098 220.5) |
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 #66C4E1 | 1.99:1 | Fails | Lc -42.7 | Non-text elements, placeholder text |
| Black text on #66C4E1 | 10.54:1 | AAA | Lc 65.6 | Content text, not long reading |
| #66C4E1 text on white | 1.99:1 | Fails | Lc 38.3 | Non-text elements, placeholder text |
| #66C4E1 text on black | 10.54:1 | AAA | Lc -64.1 | 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
#ECF8FC
oklch(97.1% 0.014 219.6)
-
Step 100
100
#D6EFF7
oklch(93.6% 0.028 219)
-
Step 200
200
#B2E2F2
oklch(88.4% 0.054 220.2)
-
Step 300
300 (this color)
#66C4E1
oklch(77.4% 0.098 220.5)
-
Step 400
400
#00B2D8
oklch(70.7% 0.129 220.4)
-
Step 500
500
#0099BA
oklch(63.2% 0.115 220.3)
-
Step 600
600
#00809D
oklch(55.6% 0.102 221.1)
-
Step 700
700
#006C84
oklch(49.2% 0.09 220.2)
-
Step 800
800
#00586D
oklch(42.6% 0.078 221.3)
-
Step 900
900
#004A5B
oklch(37.8% 0.069 219.8)
-
Step 950
950
#002C37
oklch(27.1% 0.049 219.4)
#66C4E1 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) | #B2BFE3 | 0.082 |
| Deuteranopia (no green cones) | #A0B2E1 | 0.073 |
| Tritanopia (no blue cones) | #00CECD | 0.062 |
| Achromatopsia (no color) | #B8B8B8 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66C4E1
#66C4E1
oklch(77.4% 0.098 220.5)
- #ECA085
#ECA085
oklch(77.4% 0.099 40.3)
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 #66C4E1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.025
- Lightblue #7BC8F6 ΔE 0.038
- Sky Blue #87CEEB ΔE 0.045
- Light Cornflower Blue #98C1D9 ΔE 0.049
- Sky #82CAFC ΔE 0.050
- Bright Sky Blue #02CCFE ΔE 0.051
- Light Sky Blue #87CEFA ΔE 0.054
- Light Grey Blue #9DBCD4 ΔE 0.056
Use #66C4E1 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.