#6666DA
Closest named color: Dark Periwinkle (#665FD1). oklch(57.1% 0.173 279.4), rgb(102, 102, 218).
Aa
White text reads best on this color (4.68:1).
About this color
#6666DA is a medium-dark, vivid blue. In OKLCH its lightness is 57%, its chroma 0.173 and its hue 279°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.021 away. White text reads best on it, at 4.68:1.
| Hue family | Blues |
| Lightness | medium-dark (57%) |
| Chroma | vivid (0.173) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.47:1 |
| White text | 4.68:1 |
Values
| HEX | #6666DA |
| RGB | rgb(102, 102, 218) |
| HSL | hsl(240, 61%, 63%) |
| OKLCH | oklch(57.1% 0.173 279.4) |
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 #6666DA | 4.68:1 | AA | Lc -77.7 | Fine for body text |
| Black text on #6666DA | 4.47:1 | AA large text | Lc 31.8 | Non-text elements, placeholder text |
| #6666DA text on white | 4.68:1 | AA | Lc 72.3 | Content text, not long reading |
| #6666DA text on black | 4.47:1 | AA large text | Lc -29.4 | Dividers and decoration only |
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 600.
-
Step 50
50
#F4F5FD
oklch(97.2% 0.011 280.5)
-
Step 100
100
#E6E9F9
oklch(93.6% 0.022 277.5)
-
Step 200
200
#D3D7F6
oklch(88.6% 0.043 279.7)
-
Step 300
300
#B6BCF3
oklch(81% 0.078 279.7)
-
Step 400
400
#9197ED
oklch(70.7% 0.125 279.6)
-
Step 500
500
#787BE7
oklch(63.1% 0.159 279.6)
-
Step 600
600 (this color)
#6666DA
oklch(57.1% 0.173 279.4)
-
Step 700
700
#5250B9
oklch(49.2% 0.161 279.5)
-
Step 800
800
#424295
oklch(42.6% 0.133 279.2)
-
Step 900
900
#383977
oklch(37.8% 0.103 279.5)
-
Step 950
950
#202246
oklch(27.1% 0.066 278.6)
#6666DA 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) | #2378DE | 0.071 |
| Deuteranopia (no green cones) | #0B6FD8 | 0.076 |
| Tritanopia (no blue cones) | #318096 | 0.150 |
| Achromatopsia (no color) | #747474 | 0.173 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6666DA
#6666DA
oklch(57.1% 0.173 279.4)
- #897800
#897800
oklch(57.1% 0.118 99.4)
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 #6666DA, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.021
- Light Indigo #6D5ACF ΔE 0.032
- Slate Blue #6A5ACD ΔE 0.033
- Medium Slate Blue #7B68EE ΔE 0.044
- Royal Blue #4169E1 ΔE 0.045
- Iris #6258C4 ΔE 0.047
- Warm Blue #4B57DB ΔE 0.055
- Neon Blue #4361EE ΔE 0.056
Use #6666DA 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.