#666C78
Closest named color: Dim Gray (#696969). oklch(53% 0.02 264.4), rgb(102, 108, 120).
Aa
White text reads best on this color (5.27:1).
About this color
#666C78 is a medium-dark close to neutral grey. In OKLCH its lightness is 53%, its chroma 0.020. It has too little chroma to lean warm or cool. The nearest named color is Dim Gray (#696969), ΔE 0.022 away. White text reads best on it, at 5.27:1.
| Hue family | Neutrals |
| Lightness | medium-dark (53%) |
| Chroma | close to neutral grey (0.020) |
| Temperature | neutral |
| Nearest name | Dim Gray (#696969) |
| Black text | 3.98:1 |
| White text | 5.27:1 |
Values
| HEX | #666C78 |
| RGB | rgb(102, 108, 120) |
| HSL | hsl(220, 8%, 44%) |
| OKLCH | oklch(53% 0.02 264.4) |
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 #666C78 | 5.27:1 | AA | Lc -81.6 | Fine for body text |
| Black text on #666C78 | 3.98:1 | AA large text | Lc 27.8 | Dividers and decoration only |
| #666C78 text on white | 5.27:1 | AA | Lc 76.2 | Fine for body text |
| #666C78 text on black | 3.98:1 | AA large text | Lc -25.5 | 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 600.
-
Step 50
50
#F5F5F6
oklch(97% 0.001 286.4)
-
Step 100
100
#E9EAEC
oklch(93.7% 0.003 264.5)
-
Step 200
200
#D7D9DC
oklch(88.5% 0.005 258.3)
-
Step 300
300
#BEC1C7
oklch(81% 0.009 264.5)
-
Step 400
400
#9CA1AA
oklch(70.8% 0.014 262.4)
-
Step 500
500
#848A95
oklch(63.2% 0.018 262.7)
-
Step 600
600 (this color)
#666C78
oklch(53% 0.02 264.4)
-
Step 700
700
#5B616C
oklch(49.1% 0.019 262.7)
-
Step 800
800
#4B4F58
oklch(42.7% 0.016 266.5)
-
Step 900
900
#3E4248
oklch(37.8% 0.012 258.4)
-
Step 950
950
#25262A
oklch(26.9% 0.008 274.7)
#666C78 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) | #686D79 | 0.004 |
| Deuteranopia (no green cones) | #676B78 | 0.003 |
| Tritanopia (no blue cones) | #626E70 | 0.017 |
| Achromatopsia (no color) | #6C6C6C | 0.020 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #666C78
#666C78
oklch(53% 0.02 264.4)
- #716B5F
#716B5F
oklch(53% 0.02 84.6)
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 #666C78, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dim Gray #696969 ΔE 0.022
- Battleship Gray #6C757D ΔE 0.028
- Slate #516572 ΔE 0.039
- Metallic Blue #4F738E ΔE 0.042
- Battleship Grey #6B7C85 ΔE 0.047
- Grey Blue #647D8E ΔE 0.051
- Grey Purple #826D8C ΔE 0.056
- Purple Grey #866F85 ΔE 0.056
Use #666C78 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.