#645FCB
Closest named color: Dark Periwinkle (#665FD1). oklch(54.6% 0.162 281.7), rgb(100, 95, 203).
Aa
White text reads best on this color (5.19:1).
About this color
#645FCB is a medium-dark, vivid purple. In OKLCH its lightness is 55%, its chroma 0.162 and its hue 282°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Periwinkle (#665FD1), ΔE 0.010 away. White text reads best on it, at 5.19:1.
| Hue family | Purples |
| Lightness | medium-dark (55%) |
| Chroma | vivid (0.162) |
| Temperature | cool |
| Nearest name | Dark Periwinkle (#665FD1) |
| Black text | 4.04:1 |
| White text | 5.19:1 |
Values
| HEX | #645FCB |
| RGB | rgb(100, 95, 203) |
| HSL | hsl(243, 51%, 58%) |
| OKLCH | oklch(54.6% 0.162 281.7) |
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 #645FCB | 5.19:1 | AA | Lc -80.9 | Fine for body text |
| Black text on #645FCB | 4.04:1 | AA large text | Lc 28.6 | Dividers and decoration only |
| #645FCB text on white | 5.19:1 | AA | Lc 75.5 | Fine for body text |
| #645FCB text on black | 4.04:1 | AA large text | Lc -26.2 | 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E7E9F8
oklch(93.7% 0.02 279.9)
-
Step 200
200
#D4D7F4
oklch(88.6% 0.04 280.9)
-
Step 300
300
#B8BCEF
oklch(81% 0.072 281.2)
-
Step 400
400
#9597E8
oklch(70.7% 0.118 281.9)
-
Step 500
500
#7C7BE1
oklch(63.1% 0.15 281.6)
-
Step 600
600 (this color)
#645FCB
oklch(54.6% 0.162 281.7)
-
Step 700
700
#5650B3
oklch(49.1% 0.152 281.9)
-
Step 800
800
#464291
oklch(42.7% 0.126 281.9)
-
Step 900
900
#3A3973
oklch(37.7% 0.097 281.5)
-
Step 950
950
#222244
oklch(27.1% 0.062 281.4)
#645FCB 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) | #2471CF | 0.073 |
| Deuteranopia (no green cones) | #1869C9 | 0.075 |
| Tritanopia (no blue cones) | #3B778C | 0.139 |
| Achromatopsia (no color) | #6D6D6D | 0.163 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #645FCB
#645FCB
oklch(54.6% 0.162 281.7)
- #7F7200
#7F7200
oklch(54.7% 0.114 101.5)
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 #645FCB, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Periwinkle #665FD1 ΔE 0.010
- Slate Blue #6A5ACD ΔE 0.015
- Light Indigo #6D5ACF ΔE 0.018
- Iris #6258C4 ΔE 0.020
- Warm Blue #4B57DB ΔE 0.049
- Royal Blue #4169E1 ΔE 0.055
- Neon Blue #4361EE ΔE 0.067
- Bluey Purple #6241C7 ΔE 0.067
Use #645FCB 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.