#555D66
Closest named color: Slate (#516572). oklch(47.5% 0.018 251.3), rgb(85, 93, 102).
Aa
White text reads best on this color (6.67:1).
About this color
#555D66 is a medium-dark close to neutral grey. In OKLCH its lightness is 47%, its chroma 0.018. It has too little chroma to lean warm or cool. The nearest named color is Slate (#516572), ΔE 0.026 away. White text reads best on it, at 6.67:1.
| Hue family | Neutrals |
| Lightness | medium-dark (47%) |
| Chroma | close to neutral grey (0.018) |
| Temperature | neutral |
| Nearest name | Slate (#516572) |
| Black text | 3.14:1 |
| White text | 6.67:1 |
Values
| HEX | #555D66 |
| RGB | rgb(85, 93, 102) |
| HSL | hsl(212, 9%, 37%) |
| OKLCH | oklch(47.5% 0.018 251.3) |
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 #555D66 | 6.67:1 | AA | Lc -88.0 | Fine for body text |
| Black text on #555D66 | 3.14:1 | AA large text | Lc 21.0 | Dividers and decoration only |
| #555D66 text on white | 6.67:1 | AA | Lc 83.0 | Fine for body text |
| #555D66 text on black | 3.14:1 | AA large text | Lc -18.9 | 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
#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
#9BA1A9
oklch(70.7% 0.014 255.5)
-
Step 500
500
#828A94
oklch(63% 0.018 254)
-
Step 600
600
#6B747E
oklch(55.5% 0.019 251)
-
Step 700
700 (this color)
#555D66
oklch(47.5% 0.018 251.3)
-
Step 800
800
#495057
oklch(42.8% 0.015 248.2)
-
Step 900
900
#3D4248
oklch(37.7% 0.012 253)
-
Step 950
950
#24272A
oklch(27.1% 0.007 248.1)
#555D66 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) | #5A5D66 | 0.008 |
| Deuteranopia (no green cones) | #585B66 | 0.007 |
| Tritanopia (no blue cones) | #515F60 | 0.015 |
| Achromatopsia (no color) | #5C5C5C | 0.018 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #555D66
#555D66
oklch(47.5% 0.018 251.3)
- #635B51
#635B51
oklch(47.6% 0.019 73.5)
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 #555D66, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Slate #516572 ΔE 0.026
- Dusty Grape #545775 ΔE 0.035
- YInMn Blue #415A77 ΔE 0.041
- Dim Gray #696969 ΔE 0.049
- Dusk #4E5481 ΔE 0.060
- Denim #3B638C ΔE 0.064
- Dark Green Blue #1F6357 ΔE 0.070
- Dark Aqua #05696B ΔE 0.070
Use #555D66 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.