#66B8EA
Closest named color: Vivid Sky Blue (#4CC9F0). oklch(75% 0.108 237.4), rgb(102, 184, 234).
Aa
Black text reads best on this color (9.60:1).
About this color
#66B8EA is a medium-light, moderately saturated blue. In OKLCH its lightness is 75%, its chroma 0.108 and its hue 237°. Its hue sits on the cool side of the wheel. The nearest named color is Vivid Sky Blue (#4CC9F0), ΔE 0.046 away. Black text reads best on it, at 9.60:1.
| Hue family | Blues |
| Lightness | medium-light (75%) |
| Chroma | moderately saturated (0.108) |
| Temperature | cool |
| Nearest name | Vivid Sky Blue (#4CC9F0) |
| Black text | 9.60:1 |
| White text | 2.18:1 |
Values
| HEX | #66B8EA |
| RGB | rgb(102, 184, 234) |
| HSL | hsl(203, 76%, 66%) |
| OKLCH | oklch(75% 0.108 237.4) |
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 #66B8EA | 2.18:1 | Fails | Lc -47.5 | Large or bold text, headings |
| Black text on #66B8EA | 9.60:1 | AAA | Lc 61.1 | Content text, not long reading |
| #66B8EA text on white | 2.18:1 | Fails | Lc 42.8 | Non-text elements, placeholder text |
| #66B8EA text on black | 9.60:1 | AAA | Lc -59.4 | Large or bold text, headings |
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 400.
-
Step 50
50
#F0F6FB
oklch(97% 0.009 242.8)
-
Step 100
100
#DEECF6
oklch(93.6% 0.02 238.7)
-
Step 200
200
#C3DDEF
oklch(88.4% 0.037 238.1)
-
Step 300
300
#98C8E7
oklch(81% 0.067 237)
-
Step 400
400 (this color)
#66B8EA
oklch(75% 0.108 237.4)
-
Step 500
500
#0394D2
oklch(63.2% 0.138 237.2)
-
Step 600
600
#007CB1
oklch(55.6% 0.122 237.2)
-
Step 700
700
#006896
oklch(49.1% 0.108 237.6)
-
Step 800
800
#00557C
oklch(42.7% 0.094 237.9)
-
Step 900
900
#004768
oklch(37.7% 0.083 237.5)
-
Step 950
950
#022A3F
oklch(27.1% 0.057 237.5)
#66B8EA 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) | #A1B7EC | 0.064 |
| Deuteranopia (no green cones) | #8FA9E9 | 0.055 |
| Tritanopia (no blue cones) | #00C5C9 | 0.082 |
| Achromatopsia (no color) | #AFAFAF | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66B8EA
#66B8EA
oklch(75% 0.108 237.4)
- #E29C67
#E29C67
oklch(75% 0.109 57.3)
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 #66B8EA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Vivid Sky Blue #4CC9F0 ΔE 0.046
- Deep Sky Blue #00BFFF ΔE 0.047
- Carolina Blue #8AB8FE ΔE 0.049
- Lightblue #7BC8F6 ΔE 0.050
- Bright Sky Blue #02CCFE ΔE 0.060
- Sky #82CAFC ΔE 0.061
- Light Cornflower Blue #98C1D9 ΔE 0.066
- Light Grey Blue #9DBCD4 ΔE 0.067
Use #66B8EA 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.