#645D66
Closest named color: Slate (#516572). oklch(48.8% 0.017 318.7), rgb(100, 93, 102).
Aa
White text reads best on this color (6.36:1).
About this color
#645D66 is a medium-dark close to neutral grey. In OKLCH its lightness is 49%, its chroma 0.017. It has too little chroma to lean warm or cool. The nearest named color is Slate (#516572), ΔE 0.035 away. White text reads best on it, at 6.36:1.
| Hue family | Neutrals |
| Lightness | medium-dark (49%) |
| Chroma | close to neutral grey (0.017) |
| Temperature | neutral |
| Nearest name | Slate (#516572) |
| Black text | 3.29:1 |
| White text | 6.36:1 |
Values
| HEX | #645D66 |
| RGB | rgb(100, 93, 102) |
| HSL | hsl(287, 5%, 38%) |
| OKLCH | oklch(48.8% 0.017 318.7) |
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 #645D66 | 6.36:1 | AA | Lc -86.8 | Fine for body text |
| Black text on #645D66 | 3.29:1 | AA large text | Lc 22.4 | Dividers and decoration only |
| #645D66 text on white | 6.36:1 | AA | Lc 81.7 | Fine for body text |
| #645D66 text on black | 3.29:1 | AA large text | Lc -20.2 | 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 700.
-
Step 50
50
#F6F5F6
oklch(97.1% 0.002 325.6)
-
Step 100
100
#EAE9EB
oklch(93.5% 0.003 308.4)
-
Step 200
200
#DAD8DB
oklch(88.5% 0.005 314.8)
-
Step 300
300
#C3BFC4
oklch(80.9% 0.008 319.4)
-
Step 400
400
#A49EA6
oklch(70.7% 0.013 317.7)
-
Step 500
500
#8E8690
oklch(63% 0.017 319.5)
-
Step 600
600
#78707A
oklch(55.6% 0.018 319.5)
-
Step 700
700 (this color)
#645D66
oklch(48.8% 0.017 318.7)
-
Step 800
800
#524D54
oklch(42.8% 0.013 316.4)
-
Step 900
900
#444045
oklch(37.7% 0.01 319.5)
-
Step 950
950
#282529
oklch(26.9% 0.008 317.7)
#645D66 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) | #5C5F66 | 0.013 |
| Deuteranopia (no green cones) | #5E5F66 | 0.011 |
| Tritanopia (no blue cones) | #645E60 | 0.011 |
| Achromatopsia (no color) | #5F5F5F | 0.017 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #645D66
#645D66
oklch(48.8% 0.017 318.7)
- #5B6259
#5B6259
oklch(48.7% 0.017 138.7)
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 #645D66, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Slate #516572 ΔE 0.035
- Dim Gray #696969 ΔE 0.037
- Dusty Grape #545775 ΔE 0.043
- YInMn Blue #415A77 ΔE 0.059
- Dusk #4E5481 ΔE 0.068
- Dull Purple #84597E ΔE 0.071
- Dark Mauve #874C62 ΔE 0.072
- Dark Taupe #7F684E ΔE 0.072
Use #645D66 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.