#42555E
Closest named color: Dark Slate Gray (#2F4F4F). oklch(43.7% 0.028 228.4), rgb(66, 85, 94).
Aa
White text reads best on this color (7.79:1).
About this color
#42555E is a dark close to neutral grey. In OKLCH its lightness is 44%, its chroma 0.028. It has too little chroma to lean warm or cool. The nearest named color is Dark Slate Gray (#2F4F4F), ΔE 0.040 away. White text reads best on it, at 7.79:1.
| Hue family | Neutrals |
| Lightness | dark (44%) |
| Chroma | close to neutral grey (0.028) |
| Temperature | neutral |
| Nearest name | Dark Slate Gray (#2F4F4F) |
| Black text | 2.69:1 |
| White text | 7.79:1 |
Values
| HEX | #42555E |
| RGB | rgb(66, 85, 94) |
| HSL | hsl(199, 18%, 31%) |
| OKLCH | oklch(43.7% 0.028 228.4) |
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 #42555E | 7.79:1 | AAA | Lc -91.8 | Preferred for body text |
| Black text on #42555E | 2.69:1 | Fails | Lc 16.9 | Dividers and decoration only |
| #42555E text on white | 7.79:1 | AAA | Lc 87.1 | Fine for body text |
| #42555E text on black | 2.69:1 | Fails | Lc -15.0 | 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 800.
-
Step 50
50
#F4F6F6
oklch(97.2% 0.002 197.1)
-
Step 100
100
#E7EAEC
oklch(93.5% 0.004 236.5)
-
Step 200
200
#D3DADE
oklch(88.4% 0.009 232.4)
-
Step 300
300
#B6C3C9
oklch(80.9% 0.017 227)
-
Step 400
400
#91A4AE
oklch(70.7% 0.026 230.6)
-
Step 500
500
#758E9A
oklch(63.1% 0.034 228.5)
-
Step 600
600
#5E7884
oklch(55.7% 0.035 227.8)
-
Step 700
700
#4D6570
oklch(49.2% 0.034 227.7)
-
Step 800
800 (this color)
#42555E
oklch(43.7% 0.028 228.4)
-
Step 900
900
#36444B
oklch(37.7% 0.022 229.7)
-
Step 950
950
#20282C
oklch(27.1% 0.014 229.5)
#42555E 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) | #50545E | 0.020 |
| Deuteranopia (no green cones) | #4C515E | 0.018 |
| Tritanopia (no blue cones) | #395858 | 0.020 |
| Achromatopsia (no color) | #525252 | 0.028 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #42555E
#42555E
oklch(43.7% 0.028 228.4)
- #5F4D45
#5F4D45
oklch(43.6% 0.028 45.3)
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 #42555E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Gray #2F4F4F ΔE 0.040
- YInMn Blue #415A77 ΔE 0.040
- Dusty Grape #545775 ΔE 0.048
- Petrol #005F6A ΔE 0.052
- Deep Teal #00555A ΔE 0.054
- Slate #516572 ΔE 0.058
- Dark Green Blue #1F6357 ΔE 0.059
- Dark Grey Blue #29465B ΔE 0.061
Use #42555E 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.