#66398B
Closest named color: Rebecca Purple (#663399). oklch(43.9% 0.135 307), rgb(102, 57, 139).
Aa
White text reads best on this color (8.32:1).
About this color
#66398B is a dark, moderately saturated purple. In OKLCH its lightness is 44%, its chroma 0.135 and its hue 307°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Rebecca Purple (#663399), ΔE 0.027 away. White text reads best on it, at 8.32:1.
| Hue family | Purples |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.135) |
| Temperature | in between |
| Nearest name | Rebecca Purple (#663399) |
| Black text | 2.52:1 |
| White text | 8.32:1 |
Values
| HEX | #66398B |
| RGB | rgb(102, 57, 139) |
| HSL | hsl(273, 42%, 38%) |
| OKLCH | oklch(43.9% 0.135 307) |
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 #66398B | 8.32:1 | AAA | Lc -93.0 | Preferred for body text |
| Black text on #66398B | 2.52:1 | Fails | Lc 15.6 | Dividers and decoration only |
| #66398B text on white | 8.32:1 | AAA | Lc 88.4 | Fine for body text |
| #66398B text on black | 2.52:1 | Fails | Lc -13.8 | Not readable |
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 800.
-
Step 50
50
#F7F4FB
oklch(97.1% 0.01 305.4)
-
Step 100
100
#EEE6F6
oklch(93.6% 0.023 308.2)
-
Step 200
200
#E1D2F0
oklch(88.5% 0.044 307.9)
-
Step 300
300
#CEB4E9
oklch(81% 0.078 307)
-
Step 400
400
#B58BDE
oklch(70.8% 0.126 306.7)
-
Step 500
500
#A36BD4
oklch(63.1% 0.161 307)
-
Step 600
600
#8E50C1
oklch(55.5% 0.174 306.9)
-
Step 700
700
#7940A7
oklch(49.1% 0.163 306.9)
-
Step 800
800 (this color)
#66398B
oklch(43.9% 0.135 307)
-
Step 900
900
#502F6C
oklch(37.6% 0.105 307)
-
Step 950
950
#2F1C3F
oklch(26.9% 0.067 307.6)
#66398B 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) | #1A4C8E | 0.111 |
| Deuteranopia (no green cones) | #2C4E89 | 0.099 |
| Tritanopia (no blue cones) | #60495C | 0.098 |
| Achromatopsia (no color) | #4E4E4E | 0.136 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66398B
#66398B
oklch(43.9% 0.135 307)
- #415D00
#415D00
oklch(43.9% 0.114 127.2)
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 #66398B, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Rebecca Purple #663399 ΔE 0.027
- Dark Slate Blue #483D8B ΔE 0.054
- Blueberry #464196 ΔE 0.060
- Twilight #4E518B ΔE 0.070
- Light Eggplant #894585 ΔE 0.079
- Dusk #4E5481 ΔE 0.082
- Purple #800080 ΔE 0.086
- Warm Purple #952E8F ΔE 0.092
Use #66398B 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.