#645B91
Closest named color: Dusky Blue (#475F94). oklch(50.3% 0.085 290.7), rgb(100, 91, 145).
Aa
White text reads best on this color (6.09:1).
About this color
#645B91 is a medium-dark, moderately saturated purple. In OKLCH its lightness is 50%, its chroma 0.085 and its hue 291°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Dusky Blue (#475F94), ΔE 0.041 away. White text reads best on it, at 6.09:1.
| Hue family | Purples |
| Lightness | medium-dark (50%) |
| Chroma | moderately saturated (0.085) |
| Temperature | in between |
| Nearest name | Dusky Blue (#475F94) |
| Black text | 3.44:1 |
| White text | 6.09:1 |
Values
| HEX | #645B91 |
| RGB | rgb(100, 91, 145) |
| HSL | hsl(250, 23%, 46%) |
| OKLCH | oklch(50.3% 0.085 290.7) |
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 #645B91 | 6.09:1 | AA | Lc -85.5 | Fine for body text |
| Black text on #645B91 | 3.44:1 | AA large text | Lc 23.7 | Dividers and decoration only |
| #645B91 text on white | 6.09:1 | AA | Lc 80.4 | Fine for body text |
| #645B91 text on black | 3.44:1 | AA large text | Lc -21.5 | 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
#F5F5F9
oklch(97.1% 0.005 286.3)
-
Step 100
100
#E9E9F1
oklch(93.6% 0.011 286.2)
-
Step 200
200
#D9D7E8
oklch(88.6% 0.023 291.3)
-
Step 300
300
#C0BDDA
oklch(81% 0.041 290.2)
-
Step 400
400
#A09AC7
oklch(70.7% 0.065 290.7)
-
Step 500
500
#8981B9
oklch(63.2% 0.084 290.3)
-
Step 600
600
#7369A5
oklch(55.5% 0.092 290.7)
-
Step 700
700 (this color)
#645B91
oklch(50.3% 0.085 290.7)
-
Step 800
800
#4F4873
oklch(42.8% 0.07 290.6)
-
Step 900
900
#413C5D
oklch(37.6% 0.056 290.4)
-
Step 950
950
#262336
oklch(26.8% 0.035 291.1)
#645B91 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) | #4C6393 | 0.038 |
| Deuteranopia (no green cones) | #4C6190 | 0.037 |
| Tritanopia (no blue cones) | #5A656F | 0.072 |
| Achromatopsia (no color) | #626262 | 0.085 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #645B91
#645B91
oklch(50.3% 0.085 290.7)
- #66682A
#66682A
oklch(50.2% 0.084 110.8)
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 #645B91, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusky Blue #475F94 ΔE 0.041
- Twilight #4E518B ΔE 0.047
- Dusk #4E5481 ΔE 0.048
- Muted Purple #805B87 ΔE 0.049
- Dusty Grape #545775 ΔE 0.053
- Dusty Purple #825F87 ΔE 0.056
- Denim Blue #3B5B92 ΔE 0.057
- Denim #3B638C ΔE 0.059
Use #645B91 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.