#3F555F
Closest named color: Dark Slate Gray (#2F4F4F). oklch(43.5% 0.032 227.6), rgb(63, 85, 95).
Aa
White text reads best on this color (7.84:1).
About this color
#3F555F is a dark, muted teal or cyan. In OKLCH its lightness is 44%, its chroma 0.032 and its hue 228°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Gray (#2F4F4F), ΔE 0.038 away. White text reads best on it, at 7.84:1.
| Hue family | Teals and cyans |
| Lightness | dark (44%) |
| Chroma | muted (0.032) |
| Temperature | cool |
| Nearest name | Dark Slate Gray (#2F4F4F) |
| Black text | 2.67:1 |
| White text | 7.84:1 |
Values
| HEX | #3F555F |
| RGB | rgb(63, 85, 95) |
| HSL | hsl(199, 20%, 31%) |
| OKLCH | oklch(43.5% 0.032 227.6) |
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 #3F555F | 7.84:1 | AAA | Lc -91.9 | Preferred for body text |
| Black text on #3F555F | 2.67:1 | Fails | Lc 16.8 | Dividers and decoration only |
| #3F555F text on white | 7.84:1 | AAA | Lc 87.2 | Fine for body text |
| #3F555F text on black | 2.67:1 | Fails | Lc -14.9 | 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 800.
-
Step 50
50
#F4F6F7
oklch(97.2% 0.003 228.8)
-
Step 100
100
#E6EBED
oklch(93.7% 0.006 223.5)
-
Step 200
200
#D2DBDE
oklch(88.5% 0.011 219.6)
-
Step 300
300
#B5C3CA
oklch(80.9% 0.018 229.1)
-
Step 400
400
#8EA5AF
oklch(70.8% 0.03 225.9)
-
Step 500
500
#728E9C
oklch(63% 0.038 229.7)
-
Step 600
600
#5A7886
oklch(55.5% 0.041 228.3)
-
Step 700
700
#4A6572
oklch(49% 0.038 229.2)
-
Step 800
800 (this color)
#3F555F
oklch(43.5% 0.032 227.6)
-
Step 900
900
#34444C
oklch(37.6% 0.025 229.8)
-
Step 950
950
#1F282C
oklch(27% 0.015 226.6)
#3F555F 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) | #505460 | 0.025 |
| Deuteranopia (no green cones) | #4B505F | 0.022 |
| Tritanopia (no blue cones) | #355858 | 0.022 |
| Achromatopsia (no color) | #525252 | 0.032 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F555F
#3F555F
oklch(43.5% 0.032 227.6)
- #604C42
#604C42
oklch(43.4% 0.032 48)
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 #3F555F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Gray #2F4F4F ΔE 0.038
- YInMn Blue #415A77 ΔE 0.039
- Petrol #005F6A ΔE 0.049
- Dusty Grape #545775 ΔE 0.049
- Deep Teal #00555A ΔE 0.051
- Dark Green Blue #1F6357 ΔE 0.058
- Dark Grey Blue #29465B ΔE 0.058
- Slate #516572 ΔE 0.060
Use #3F555F 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.