#664FD1
Closest named color: Slate Blue (#6A5ACD). oklch(52.5% 0.191 285.9), rgb(102, 79, 209).
Aa
White text reads best on this color (5.82:1).
About this color
#664FD1 is a medium-dark, vivid purple. In OKLCH its lightness is 52%, its chroma 0.191 and its hue 286°. Its hue sits on the cool side of the wheel. The nearest named color is Slate Blue (#6A5ACD), ΔE 0.027 away. White text reads best on it, at 5.82:1.
| Hue family | Purples |
| Lightness | medium-dark (52%) |
| Chroma | vivid (0.191) |
| Temperature | cool |
| Nearest name | Slate Blue (#6A5ACD) |
| Black text | 3.60:1 |
| White text | 5.82:1 |
Values
| HEX | #664FD1 |
| RGB | rgb(102, 79, 209) |
| HSL | hsl(251, 59%, 56%) |
| OKLCH | oklch(52.5% 0.191 285.9) |
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 #664FD1 | 5.82:1 | AA | Lc -83.9 | Fine for body text |
| Black text on #664FD1 | 3.60:1 | AA large text | Lc 25.4 | Dividers and decoration only |
| #664FD1 text on white | 5.82:1 | AA | Lc 78.7 | Fine for body text |
| #664FD1 text on black | 3.60:1 | AA large text | Lc -23.1 | 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
#F4F4FD
oklch(97% 0.012 286.2)
-
Step 100
100
#E8E8FA
oklch(93.6% 0.024 285.9)
-
Step 200
200
#D6D5F8
oklch(88.5% 0.048 286.7)
-
Step 300
300
#BBB9F6
oklch(80.9% 0.086 285.8)
-
Step 400
400
#9A92F2
oklch(70.7% 0.138 286.1)
-
Step 500
500
#8374ED
oklch(63.1% 0.176 285.9)
-
Step 600
600 (this color)
#664FD1
oklch(52.5% 0.191 285.9)
-
Step 700
700
#5D48BF
oklch(49.2% 0.178 285.9)
-
Step 800
800
#4B3C9A
oklch(42.7% 0.147 285.6)
-
Step 900
900
#3E347B
oklch(37.6% 0.116 285.8)
-
Step 950
950
#241F48
oklch(26.9% 0.074 285.9)
#664FD1 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) | #0069D5 | 0.097 |
| Deuteranopia (no green cones) | #0061CE | 0.093 |
| Tritanopia (no blue cones) | #3D6E89 | 0.158 |
| Achromatopsia (no color) | #656565 | 0.192 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #664FD1
#664FD1
oklch(52.5% 0.191 285.9)
- #736D00
#736D00
oklch(52.3% 0.112 105.9)
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 #664FD1, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Slate Blue #6A5ACD ΔE 0.027
- Light Indigo #6D5ACF ΔE 0.029
- Iris #6258C4 ΔE 0.030
- Bluey Purple #6241C7 ΔE 0.034
- Dark Periwinkle #665FD1 ΔE 0.036
- Warm Blue #4B57DB ΔE 0.043
- Blurple #5539CC ΔE 0.056
- Blue With A Hint Of Purple #533CC6 ΔE 0.056
Use #664FD1 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.