#3F3740
Closest named color: Onyx (#343A40). oklch(34.9% 0.019 322.5), rgb(63, 55, 64).
Aa
White text reads best on this color (11.46:1).
About this color
#3F3740 is a dark close to neutral grey. In OKLCH its lightness is 35%, its chroma 0.019. It has too little chroma to lean warm or cool. The nearest named color is Onyx (#343A40), ΔE 0.020 away. White text reads best on it, at 11.46:1.
| Hue family | Neutrals |
| Lightness | dark (35%) |
| Chroma | close to neutral grey (0.019) |
| Temperature | neutral |
| Nearest name | Onyx (#343A40) |
| Black text | 1.83:1 |
| White text | 11.46:1 |
Values
| HEX | #3F3740 |
| RGB | rgb(63, 55, 64) |
| HSL | hsl(293, 8%, 23%) |
| OKLCH | oklch(34.9% 0.019 322.5) |
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 #3F3740 | 11.46:1 | AAA | Lc -100.1 | Preferred for body text |
| Black text on #3F3740 | 1.83:1 | Fails | Lc 7.4 | Not readable |
| #3F3740 text on white | 11.46:1 | AAA | Lc 96.4 | Preferred for body text |
| #3F3740 text on black | 1.83:1 | Fails | Lc 0.0 | Not readable |
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 900.
-
Step 50
50
#F6F5F6
oklch(97.1% 0.002 325.6)
-
Step 100
100
#EBE9EB
oklch(93.6% 0.003 325.6)
-
Step 200
200
#DCD7DC
oklch(88.5% 0.009 325.6)
-
Step 300
300
#C5BEC6
oklch(81% 0.013 321.9)
-
Step 400
400
#A89CA9
oklch(70.7% 0.023 323.5)
-
Step 500
500
#928494
oklch(63.1% 0.029 322)
-
Step 600
600
#7C6D7E
oklch(55.5% 0.032 322.3)
-
Step 700
700
#695B6B
oklch(49% 0.031 322)
-
Step 800
800
#564B57
oklch(42.8% 0.024 323.4)
-
Step 900
900 (this color)
#3F3740
oklch(34.9% 0.019 322.5)
-
Step 950
950
#29252A
oklch(27.1% 0.011 319.5)
#3F3740 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) | #363940 | 0.016 |
| Deuteranopia (no green cones) | #383A40 | 0.015 |
| Tritanopia (no blue cones) | #3F383A | 0.012 |
| Achromatopsia (no color) | #393939 | 0.019 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F3740
#3F3740
oklch(34.9% 0.019 322.5)
- #353D34
#353D34
oklch(35% 0.019 142.1)
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 #3F3740, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Onyx #343A40 ΔE 0.020
- Charcoal Grey #3C4142 ΔE 0.032
- Gunmetal #293241 ΔE 0.043
- Dark Blue Grey #1F3B4D ΔE 0.049
- Space Cadet #2B2D42 ΔE 0.051
- Charcoal #264653 ΔE 0.056
- Dark Grey Blue #29465B ΔE 0.060
- Prussian Blue #1D3557 ΔE 0.066
Use #3F3740 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.