#664CB5
Closest named color: Iris (#6258C4). oklch(49.9% 0.159 290.9), rgb(102, 76, 181).
Aa
White text reads best on this color (6.42:1).
About this color
#664CB5 is a medium-dark, vivid purple. In OKLCH its lightness is 50%, its chroma 0.159 and its hue 291°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Iris (#6258C4), ΔE 0.035 away. White text reads best on it, at 6.42:1.
| Hue family | Purples |
| Lightness | medium-dark (50%) |
| Chroma | vivid (0.159) |
| Temperature | in between |
| Nearest name | Iris (#6258C4) |
| Black text | 3.26:1 |
| White text | 6.42:1 |
Values
| HEX | #664CB5 |
| RGB | rgb(102, 76, 181) |
| HSL | hsl(255, 42%, 50%) |
| OKLCH | oklch(49.9% 0.159 290.9) |
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 #664CB5 | 6.42:1 | AA | Lc -86.7 | Fine for body text |
| Black text on #664CB5 | 3.26:1 | AA large text | Lc 22.4 | Dividers and decoration only |
| #664CB5 text on white | 6.42:1 | AA | Lc 81.6 | Fine for body text |
| #664CB5 text on black | 3.26:1 | AA large text | Lc -20.3 | 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 700.
-
Step 50
50
#F5F4FC
oklch(97% 0.011 292)
-
Step 100
100
#E9E8F8
oklch(93.6% 0.021 288.9)
-
Step 200
200
#D8D5F4
oklch(88.5% 0.042 289.9)
-
Step 300
300
#C0B8EF
oklch(80.8% 0.077 291.2)
-
Step 400
400
#A192E7
oklch(70.7% 0.123 291)
-
Step 500
500
#8B75E0
oklch(63.1% 0.157 290.7)
-
Step 600
600
#765BCE
oklch(55.6% 0.171 290.6)
-
Step 700
700 (this color)
#664CB5
oklch(49.9% 0.159 290.9)
-
Step 800
800
#513D90
oklch(42.6% 0.132 290.9)
-
Step 900
900
#433573
oklch(37.7% 0.103 291.1)
-
Step 950
950
#272043
oklch(27.1% 0.064 290.7)
#664CB5 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) | #0560B8 | 0.099 |
| Deuteranopia (no green cones) | #115CB3 | 0.095 |
| Tritanopia (no blue cones) | #4F6379 | 0.129 |
| Achromatopsia (no color) | #5F5F5F | 0.160 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #664CB5
#664CB5
oklch(49.9% 0.159 290.9)
- #666800
#666800
oklch(49.9% 0.11 111.1)
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 #664CB5, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Iris #6258C4 ΔE 0.035
- Bluey Purple #6241C7 ΔE 0.039
- Slate Blue #6A5ACD ΔE 0.049
- Light Indigo #6D5ACF ΔE 0.052
- Blue With A Hint Of Purple #533CC6 ΔE 0.057
- Dark Periwinkle #665FD1 ΔE 0.060
- Blurple #5539CC ΔE 0.064
- Rebecca Purple #663399 ΔE 0.068
Use #664CB5 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.