#66637A
Closest named color: Slate (#516572). oklch(51.1% 0.036 291), rgb(102, 99, 122).
Aa
White text reads best on this color (5.78:1).
About this color
#66637A is a medium-dark, muted purple. In OKLCH its lightness is 51%, its chroma 0.036 and its hue 291°. Its hue sits between the warm and cool halves of the wheel. The nearest named color is Slate (#516572), ΔE 0.035 away. White text reads best on it, at 5.78:1.
| Hue family | Purples |
| Lightness | medium-dark (51%) |
| Chroma | muted (0.036) |
| Temperature | in between |
| Nearest name | Slate (#516572) |
| Black text | 3.63:1 |
| White text | 5.78:1 |
Values
| HEX | #66637A |
| RGB | rgb(102, 99, 122) |
| HSL | hsl(248, 10%, 43%) |
| OKLCH | oklch(51.1% 0.036 291) |
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 #66637A | 5.78:1 | AA | Lc -84.2 | Fine for body text |
| Black text on #66637A | 3.63:1 | AA large text | Lc 25.1 | Dividers and decoration only |
| #66637A text on white | 5.78:1 | AA | Lc 79.0 | Fine for body text |
| #66637A text on black | 3.63:1 | AA large text | Lc -22.8 | 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
#F5F5F7
oklch(97.1% 0.003 286.4)
-
Step 100
100
#EAE9ED
oklch(93.6% 0.005 297.7)
-
Step 200
200
#D9D8DF
oklch(88.5% 0.01 292.8)
-
Step 300
300
#C0BFCB
oklch(80.9% 0.017 289.9)
-
Step 400
400
#A09EB1
oklch(70.7% 0.027 290.5)
-
Step 500
500
#89869E
oklch(63.1% 0.036 291.1)
-
Step 600
600
#737089
oklch(55.7% 0.039 290.6)
-
Step 700
700 (this color)
#66637A
oklch(51.1% 0.036 291)
-
Step 800
800
#4F4C5F
oklch(42.7% 0.031 292.3)
-
Step 900
900
#41404D
oklch(37.8% 0.022 288.8)
-
Step 950
950
#26252D
oklch(26.9% 0.015 291.1)
#66637A 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) | #5E667B | 0.014 |
| Deuteranopia (no green cones) | #5E6579 | 0.013 |
| Tritanopia (no blue cones) | #62676B | 0.031 |
| Achromatopsia (no color) | #666666 | 0.036 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #66637A
#66637A
oklch(51.1% 0.036 291)
- #676951
#676951
oklch(51.2% 0.036 111.5)
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 #66637A, 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 0.038
- Dusty Grape #545775 ΔE 0.047
- Metallic Blue #4F738E ΔE 0.053
- Dusty Purple #825F87 ΔE 0.053
- Battleship Gray #6C757D ΔE 0.054
- Muted Purple #805B87 ΔE 0.054
- Dull Purple #84597E ΔE 0.056
Use #66637A 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.