#66ACEE
Closest named color: Carolina Blue (#8AB8FE). oklch(72.6% 0.12 248.5), rgb(102, 172, 238).
Aa
Black text reads best on this color (8.70:1).
About this color
#66ACEE is a medium-light, moderately saturated blue. In OKLCH its lightness is 73%, its chroma 0.120 and its hue 248°. Its hue sits on the cool side of the wheel. The nearest named color is Carolina Blue (#8AB8FE), ΔE 0.056 away. Black text reads best on it, at 8.70:1.
| Hue family | Blues |
| Lightness | medium-light (73%) |
| Chroma | moderately saturated (0.120) |
| Temperature | cool |
| Nearest name | Carolina Blue (#8AB8FE) |
| Black text | 8.70:1 |
| White text | 2.41:1 |
Values
| HEX | #66ACEE |
| RGB | rgb(102, 172, 238) |
| HSL | hsl(209, 80%, 67%) |
| OKLCH | oklch(72.6% 0.12 248.5) |
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 #66ACEE | 2.41:1 | Fails | Lc -52.3 | Large or bold text, headings |
| Black text on #66ACEE | 8.70:1 | AAA | Lc 56.6 | Large or bold text, headings |
| #66ACEE text on white | 2.41:1 | Fails | Lc 47.3 | Large or bold text, headings |
| #66ACEE text on black | 8.70:1 | AAA | Lc -54.7 | 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
#F0F6FC
oklch(97% 0.01 247.9)
-
Step 100
100
#DFEBF8
oklch(93.5% 0.022 250.2)
-
Step 200
200
#C4DCF4
oklch(88.4% 0.042 248.3)
-
Step 300
300
#9BC5EF
oklch(80.8% 0.075 248.8)
-
Step 400
400 (this color)
#66ACEE
oklch(72.6% 0.12 248.5)
-
Step 500
500
#298EE1
oklch(63.1% 0.154 248.5)
-
Step 600
600
#0077C7
oklch(55.7% 0.152 248.5)
-
Step 700
700
#0064A8
oklch(49.2% 0.133 248.3)
-
Step 800
800
#00518B
oklch(42.6% 0.117 248.8)
-
Step 900
900
#044473
oklch(37.7% 0.099 248.1)
-
Step 950
950
#082844
oklch(27% 0.064 249)
#66ACEE 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) | #90AEF1 | 0.047 |
| Deuteranopia (no green cones) | #7EA1ED | 0.036 |
| Tritanopia (no blue cones) | #00BBC3 | 0.099 |
| Achromatopsia (no color) | #A7A7A7 | 0.120 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66ACEE
#66ACEE
oklch(72.6% 0.12 248.5)
- #D7974B
#D7974B
oklch(72.5% 0.12 68.5)
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 #66ACEE, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Carolina Blue #8AB8FE ΔE 0.056
- Deep Sky Blue #00BFFF ΔE 0.060
- Cornflower Blue #6495ED ΔE 0.062
- Periwinkle Blue #8F99FB ΔE 0.070
- Chefchaouen Blue #4895EF ΔE 0.072
- Vivid Sky Blue #4CC9F0 ΔE 0.079
- Lightblue #7BC8F6 ΔE 0.081
- Greyblue #77A1B5 ΔE 0.082
Use #66ACEE 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.