#666F78
Closest named color: Battleship Gray (#6C757D). oklch(53.7% 0.018 248.2), rgb(102, 111, 120).
Aa
White text reads best on this color (5.10:1).
About this color
#666F78 is a medium-dark close to neutral grey. In OKLCH its lightness is 54%, its chroma 0.018. It has too little chroma to lean warm or cool. The nearest named color is Battleship Gray (#6C757D), ΔE 0.020 away. White text reads best on it, at 5.10:1.
| Hue family | Neutrals |
| Lightness | medium-dark (54%) |
| Chroma | close to neutral grey (0.018) |
| Temperature | neutral |
| Nearest name | Battleship Gray (#6C757D) |
| Black text | 4.10:1 |
| White text | 5.10:1 |
Values
| HEX | #666F78 |
| RGB | rgb(102, 111, 120) |
| HSL | hsl(210, 8%, 44%) |
| OKLCH | oklch(53.7% 0.018 248.2) |
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 #666F78 | 5.10:1 | AA | Lc -80.6 | Fine for body text |
| Black text on #666F78 | 4.10:1 | AA large text | Lc 28.8 | Dividers and decoration only |
| #666F78 text on white | 5.10:1 | AA | Lc 75.3 | Fine for body text |
| #666F78 text on black | 4.10:1 | AA large text | Lc -26.5 | 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
#E9EAEB
oklch(93.7% 0.002 247.8)
-
Step 200
200
#D7D9DC
oklch(88.5% 0.005 258.3)
-
Step 300
300
#BDC1C6
oklch(80.9% 0.008 253.9)
-
Step 400
400
#9BA1A8
oklch(70.6% 0.012 252.1)
-
Step 500
500
#828B93
oklch(63.2% 0.016 244.8)
-
Step 600
600 (this color)
#666F78
oklch(53.7% 0.018 248.2)
-
Step 700
700
#5A626A
oklch(49.2% 0.016 248.2)
-
Step 800
800
#495056
oklch(42.7% 0.013 243.9)
-
Step 900
900
#3D4247
oklch(37.6% 0.011 248.1)
-
Step 950
950
#24272A
oklch(27.1% 0.007 248.1)
#666F78 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) | #6C6F78 | 0.009 |
| Deuteranopia (no green cones) | #6A6D78 | 0.008 |
| Tritanopia (no blue cones) | #627172 | 0.014 |
| Achromatopsia (no color) | #6E6E6E | 0.018 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #666F78
#666F78
oklch(53.7% 0.018 248.2)
- #756C63
#756C63
oklch(53.7% 0.018 67.4)
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 #666F78, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Battleship Gray #6C757D ΔE 0.020
- Dim Gray #696969 ΔE 0.024
- Battleship Grey #6B7C85 ΔE 0.039
- Metallic Blue #4F738E ΔE 0.041
- Slate #516572 ΔE 0.044
- Grey Blue #647D8E ΔE 0.045
- Purple Grey #866F85 ΔE 0.055
- Grey Purple #826D8C ΔE 0.056
Use #666F78 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.