#6663E9
Closest named color: Medium Slate Blue (#7B68EE). oklch(57.6% 0.197 279.2), rgb(102, 99, 233).
Aa
White text reads best on this color (4.63:1).
About this color
#6663E9 is a medium-dark, vivid blue. In OKLCH its lightness is 58%, its chroma 0.197 and its hue 279°. Its hue sits on the cool side of the wheel. The nearest named color is Medium Slate Blue (#7B68EE), ΔE 0.035 away. White text reads best on it, at 4.63:1.
| Hue family | Blues |
| Lightness | medium-dark (58%) |
| Chroma | vivid (0.197) |
| Temperature | cool |
| Nearest name | Medium Slate Blue (#7B68EE) |
| Black text | 4.52:1 |
| White text | 4.63:1 |
Values
| HEX | #6663E9 |
| RGB | rgb(102, 99, 233) |
| HSL | hsl(241, 75%, 65%) |
| OKLCH | oklch(57.6% 0.197 279.2) |
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 #6663E9 | 4.63:1 | AA | Lc -77.3 | Fine for body text |
| Black text on #6663E9 | 4.52:1 | AA | Lc 32.3 | Non-text elements, placeholder text |
| #6663E9 text on white | 4.63:1 | AA | Lc 71.8 | Content text, not long reading |
| #6663E9 text on black | 4.52:1 | AA | Lc -29.8 | 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
#F3F5FE
oklch(97.1% 0.012 276.1)
-
Step 100
100
#E6E8FB
oklch(93.5% 0.026 281.1)
-
Step 200
200
#D2D6FA
oklch(88.4% 0.05 280.3)
-
Step 300
300
#B4BBFA
oklch(80.9% 0.089 279.3)
-
Step 400
400
#8F95F7
oklch(70.7% 0.142 279.4)
-
Step 500
500
#7677F3
oklch(63% 0.181 279.5)
-
Step 600
600 (this color)
#6663E9
oklch(57.6% 0.197 279.2)
-
Step 700
700
#504BC4
oklch(49% 0.183 279.1)
-
Step 800
800
#423E9F
oklch(42.7% 0.152 279.6)
-
Step 900
900
#37367E
oklch(37.6% 0.119 279.7)
-
Step 950
950
#20214A
oklch(27.1% 0.074 279.2)
#6663E9 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) | #007AED | 0.083 |
| Deuteranopia (no green cones) | #006FE6 | 0.078 |
| Tritanopia (no blue cones) | #1C839C | 0.171 |
| Achromatopsia (no color) | #757575 | 0.197 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #6663E9
#6663E9
oklch(57.6% 0.197 279.2)
- #8B7A00
#8B7A00
oklch(57.7% 0.12 99.5)
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 #6663E9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Medium Slate Blue #7B68EE ΔE 0.035
- Dark Periwinkle #665FD1 ΔE 0.037
- Light Indigo #6D5ACF ΔE 0.044
- Neon Blue #4361EE ΔE 0.045
- Slate Blue #6A5ACD ΔE 0.046
- Royal Blue #4169E1 ΔE 0.047
- Warm Blue #4B57DB ΔE 0.054
- Cornflower #6A79F7 ΔE 0.055
Use #6663E9 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.