#40575C
Closest named color: Dark Slate Gray (#2F4F4F). oklch(44% 0.029 212.5), rgb(64, 87, 92).
Aa
White text reads best on this color (7.67:1).
About this color
#40575C is a dark close to neutral grey. In OKLCH its lightness is 44%, its chroma 0.029. It has too little chroma to lean warm or cool. The nearest named color is Dark Slate Gray (#2F4F4F), ΔE 0.039 away. White text reads best on it, at 7.67:1.
| Hue family | Neutrals |
| Lightness | dark (44%) |
| Chroma | close to neutral grey (0.029) |
| Temperature | neutral |
| Nearest name | Dark Slate Gray (#2F4F4F) |
| Black text | 2.73:1 |
| White text | 7.67:1 |
Values
| HEX | #40575C |
| RGB | rgb(64, 87, 92) |
| HSL | hsl(191, 18%, 31%) |
| OKLCH | oklch(44% 0.029 212.5) |
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 #40575C | 7.67:1 | AAA | Lc -91.4 | Preferred for body text |
| Black text on #40575C | 2.73:1 | Fails | Lc 17.4 | Dividers and decoration only |
| #40575C text on white | 7.67:1 | AAA | Lc 86.7 | Fine for body text |
| #40575C text on black | 2.73:1 | Fails | Lc -15.4 | 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
#E6EBEC
oklch(93.7% 0.006 211)
-
Step 200
200
#D2DBDD
oklch(88.5% 0.01 212.5)
-
Step 300
300
#B5C4C7
oklch(81% 0.017 211)
-
Step 400
400
#8EA5AB
oklch(70.6% 0.027 215.2)
-
Step 500
500
#728F96
oklch(63% 0.034 214.1)
-
Step 600
600
#5A7A80
oklch(55.7% 0.038 210.4)
-
Step 700
700
#49666D
oklch(49% 0.036 214.3)
-
Step 800
800 (this color)
#40575C
oklch(44% 0.029 212.5)
-
Step 900
900
#344549
oklch(37.7% 0.023 213.7)
-
Step 950
950
#1F282B
oklch(26.9% 0.014 220.1)
#40575C 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) | #53555C | 0.027 |
| Deuteranopia (no green cones) | #4E525C | 0.024 |
| Tritanopia (no blue cones) | #375958 | 0.016 |
| Achromatopsia (no color) | #535353 | 0.029 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #40575C
#40575C
oklch(44% 0.029 212.5)
- #624D48
#624D48
oklch(44% 0.03 33.7)
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 #40575C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Gray #2F4F4F ΔE 0.039
- YInMn Blue #415A77 ΔE 0.044
- Petrol #005F6A ΔE 0.048
- Dark Green Blue #1F6357 ΔE 0.051
- Deep Teal #00555A ΔE 0.052
- Dusty Grape #545775 ΔE 0.053
- Slate #516572 ΔE 0.057
- Dark Aqua #05696B ΔE 0.061
Use #40575C 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.