#66BCEE
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(76.1% 0.11 236.2), rgb(102, 188, 238).
Aa
Black text reads best on this color (9.99:1).
About this color
#66BCEE is a medium-light, moderately saturated blue. In OKLCH its lightness is 76%, its chroma 0.110 and its hue 236°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.037 away. Black text reads best on it, at 9.99:1.
| Hue family | Blues |
| Lightness | medium-light (76%) |
| Chroma | moderately saturated (0.110) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 9.99:1 |
| White text | 2.10:1 |
Values
| HEX | #66BCEE |
| RGB | rgb(102, 188, 238) |
| HSL | hsl(202, 80%, 67%) |
| OKLCH | oklch(76.1% 0.11 236.2) |
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 #66BCEE | 2.10:1 | Fails | Lc -45.5 | Large or bold text, headings |
| Black text on #66BCEE | 9.99:1 | AAA | Lc 63.0 | Content text, not long reading |
| #66BCEE text on white | 2.10:1 | Fails | Lc 40.9 | Non-text elements, placeholder text |
| #66BCEE text on black | 9.99:1 | AAA | Lc -61.3 | 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
#EDF7FE
oklch(97.1% 0.014 238)
-
Step 100
100
#D7EEFD
oklch(93.7% 0.032 236.3)
-
Step 200
200
#B3E0FD
oklch(88.5% 0.062 236.7)
-
Step 300
300 (this color)
#66BCEE
oklch(76.1% 0.11 236.2)
-
Step 400
400
#00ADF2
oklch(70.7% 0.152 236.1)
-
Step 500
500
#0094D0
oklch(63.1% 0.136 236.2)
-
Step 600
600
#007CB0
oklch(55.5% 0.121 236.7)
-
Step 700
700
#006894
oklch(49% 0.106 236.4)
-
Step 800
800
#00567A
oklch(42.8% 0.091 235.4)
-
Step 900
900
#004767
oklch(37.7% 0.082 236.6)
-
Step 950
950
#002A3F
oklch(27% 0.059 236.5)
#66BCEE 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) | #A5BBF0 | 0.067 |
| Deuteranopia (no green cones) | #92ADED | 0.056 |
| Tritanopia (no blue cones) | #00C9CD | 0.082 |
| Achromatopsia (no color) | #B3B3B3 | 0.110 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66BCEE
#66BCEE
oklch(76.1% 0.11 236.2)
- #E79F6A
#E79F6A
oklch(76.2% 0.11 56.6)
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 #66BCEE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.037
- Lightblue #7BC8F6 ΔE 0.040
- Deep Sky Blue #00BFFF ΔE 0.045
- Carolina Blue #8AB8FE ΔE 0.046
- Sky #82CAFC ΔE 0.051
- Bright Sky Blue #02CCFE ΔE 0.052
- Light Sky Blue #87CEFA ΔE 0.062
- Light Cornflower Blue #98C1D9 ΔE 0.062
Use #66BCEE 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.