#66BBEE
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(75.9% 0.111 237), rgb(102, 187, 238).
Aa
Black text reads best on this color (9.90:1).
About this color
#66BBEE is a medium-light, moderately saturated blue. In OKLCH its lightness is 76%, its chroma 0.111 and its hue 237°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.039 away. Black text reads best on it, at 9.90:1.
| Hue family | Blues |
| Lightness | medium-light (76%) |
| Chroma | moderately saturated (0.111) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 9.90:1 |
| White text | 2.11:1 |
Values
| HEX | #66BBEE |
| RGB | rgb(102, 187, 238) |
| HSL | hsl(203, 80%, 67%) |
| OKLCH | oklch(75.9% 0.111 237) |
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 #66BBEE | 2.11:1 | Fails | Lc -46.0 | Large or bold text, headings |
| Black text on #66BBEE | 9.90:1 | AAA | Lc 62.6 | Content text, not long reading |
| #66BBEE text on white | 2.11:1 | Fails | Lc 41.4 | Non-text elements, placeholder text |
| #66BBEE text on black | 9.90:1 | AAA | Lc -60.9 | 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)
#66BBEE
oklch(75.9% 0.111 237)
-
Step 400
400
#00ADF4
oklch(70.8% 0.154 236.9)
-
Step 500
500
#0094D2
oklch(63.2% 0.138 237.1)
-
Step 600
600
#007CB1
oklch(55.6% 0.122 237.2)
-
Step 700
700
#006895
oklch(49% 0.107 237)
-
Step 800
800
#00557B
oklch(42.6% 0.093 237.2)
-
Step 900
900
#004767
oklch(37.7% 0.082 236.6)
-
Step 950
950
#002A3F
oklch(27% 0.059 236.5)
#66BBEE 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) | #A3BAF0 | 0.065 |
| Deuteranopia (no green cones) | #91ACED | 0.056 |
| Tritanopia (no blue cones) | #00C8CC | 0.083 |
| Achromatopsia (no color) | #B2B2B2 | 0.111 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66BBEE
#66BBEE
oklch(75.9% 0.111 237)
- #E69E68
#E69E68
oklch(75.8% 0.111 57)
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 #66BBEE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.039
- Lightblue #7BC8F6 ΔE 0.043
- Deep Sky Blue #00BFFF ΔE 0.045
- Carolina Blue #8AB8FE ΔE 0.046
- Sky #82CAFC ΔE 0.053
- Bright Sky Blue #02CCFE ΔE 0.054
- Light Cornflower Blue #98C1D9 ΔE 0.063
- Light Sky Blue #87CEFA ΔE 0.064
Use #66BBEE 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.