#66BFEE
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(76.8% 0.109 233.7), rgb(102, 191, 238).
Aa
Black text reads best on this color (10.25:1).
About this color
#66BFEE is a medium-light, moderately saturated blue. In OKLCH its lightness is 77%, its chroma 0.109 and its hue 234°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.030 away. Black text reads best on it, at 10.25:1.
| Hue family | Blues |
| Lightness | medium-light (77%) |
| Chroma | moderately saturated (0.109) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 10.25:1 |
| White text | 2.04:1 |
Values
| HEX | #66BFEE |
| RGB | rgb(102, 191, 238) |
| HSL | hsl(201, 80%, 67%) |
| OKLCH | oklch(76.8% 0.109 233.7) |
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 #66BFEE | 2.04:1 | Fails | Lc -44.2 | Non-text elements, placeholder text |
| Black text on #66BFEE | 10.25:1 | AAA | Lc 64.2 | Content text, not long reading |
| #66BFEE text on white | 2.04:1 | Fails | Lc 39.7 | Non-text elements, placeholder text |
| #66BFEE text on black | 10.25:1 | AAA | Lc -62.6 | 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
#ECF7FE
oklch(97% 0.015 235.4)
-
Step 100
100
#D6EEFC
oklch(93.6% 0.032 233.3)
-
Step 200
200
#B2E1FB
oklch(88.5% 0.06 232.5)
-
Step 300
300 (this color)
#66BFEE
oklch(76.8% 0.109 233.7)
-
Step 400
400
#00AEED
oklch(70.7% 0.147 233.5)
-
Step 500
500
#0095CC
oklch(63.1% 0.132 233.7)
-
Step 600
600
#007DAC
oklch(55.5% 0.116 233.8)
-
Step 700
700
#006991
oklch(49% 0.102 233.6)
-
Step 800
800
#005678
oklch(42.7% 0.089 233.9)
-
Step 900
900
#004865
oklch(37.8% 0.079 233.7)
-
Step 950
950
#002A3D
oklch(26.9% 0.056 233.8)
#66BFEE 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) | #A8BDF0 | 0.070 |
| Deuteranopia (no green cones) | #95AFED | 0.060 |
| Tritanopia (no blue cones) | #00CCCF | 0.079 |
| Achromatopsia (no color) | #B5B5B5 | 0.109 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66BFEE
#66BFEE
oklch(76.8% 0.109 233.7)
- #EAA070
#EAA070
oklch(76.8% 0.109 53.4)
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 #66BFEE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.030
- Lightblue #7BC8F6 ΔE 0.034
- Sky #82CAFC ΔE 0.045
- Deep Sky Blue #00BFFF ΔE 0.046
- Bright Sky Blue #02CCFE ΔE 0.047
- Carolina Blue #8AB8FE ΔE 0.049
- Light Sky Blue #87CEFA ΔE 0.055
- Sky Blue #87CEEB ΔE 0.056
Use #66BFEE 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.