#666C63
Closest named color: Dim Gray (#696969). oklch(52.3% 0.016 135), rgb(102, 108, 99).
Aa
White text reads best on this color (5.39:1).
About this color
#666C63 is a medium-dark close to neutral grey. In OKLCH its lightness is 52%, its chroma 0.016. It has too little chroma to lean warm or cool. The nearest named color is Dim Gray (#696969), ΔE 0.016 away. White text reads best on it, at 5.39:1.
| Hue family | Neutrals |
| Lightness | medium-dark (52%) |
| Chroma | close to neutral grey (0.016) |
| Temperature | neutral |
| Nearest name | Dim Gray (#696969) |
| Black text | 3.89:1 |
| White text | 5.39:1 |
Values
| HEX | #666C63 |
| RGB | rgb(102, 108, 99) |
| HSL | hsl(100, 4%, 41%) |
| OKLCH | oklch(52.3% 0.016 135) |
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 #666C63 | 5.39:1 | AA | Lc -82.3 | Fine for body text |
| Black text on #666C63 | 3.89:1 | AA large text | Lc 27.1 | Dividers and decoration only |
| #666C63 text on white | 5.39:1 | AA | Lc 76.9 | Fine for body text |
| #666C63 text on black | 3.89:1 | AA large text | Lc -24.8 | 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
#F5F5F5
oklch(97% 0 0)
-
Step 100
100
#E9EAE9
oklch(93.6% 0.002 145.6)
-
Step 200
200
#D8DAD7
oklch(88.6% 0.005 134.9)
-
Step 300
300
#BEC2BD
oklch(80.9% 0.008 139.4)
-
Step 400
400
#9DA29B
oklch(70.6% 0.012 136.6)
-
Step 500
500
#858C82
oklch(63.1% 0.017 136.1)
-
Step 600
600
#6F766C
oklch(55.7% 0.017 136.1)
-
Step 700
700 (this color)
#666C63
oklch(52.3% 0.016 135)
-
Step 800
800
#4C514A
oklch(42.8% 0.013 136.6)
-
Step 900
900
#3F433D
oklch(37.7% 0.011 135)
-
Step 950
950
#252724
oklch(27% 0.006 134.9)
#666C63 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) | #6D6A63 | 0.012 |
| Deuteranopia (no green cones) | #6C6A63 | 0.010 |
| Tritanopia (no blue cones) | #666B69 | 0.011 |
| Achromatopsia (no color) | #6A6A6A | 0.016 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #666C63
#666C63
oklch(52.3% 0.016 135)
- #6D6770
#6D6770
oklch(52.2% 0.016 314.7)
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 #666C63, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dim Gray #696969 ΔE 0.016
- Battleship Gray #6C757D ΔE 0.043
- Dark Taupe #7F684E ΔE 0.045
- Slate #516572 ΔE 0.047
- Grey Brown #7F7053 ΔE 0.048
- Battleship Grey #6B7C85 ΔE 0.061
- Dull Brown #876E4B ΔE 0.061
- Dark Moss Green #606C38 ΔE 0.063
Use #666C63 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.