#3F455D
Closest named color: Dark Grey Blue (#29465B). oklch(39.5% 0.041 273.5), rgb(63, 69, 93).
Aa
White text reads best on this color (9.45:1).
About this color
#3F455D is a dark, muted blue. In OKLCH its lightness is 40%, its chroma 0.041 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.030 away. White text reads best on it, at 9.45:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | muted (0.041) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 2.22:1 |
| White text | 9.45:1 |
Values
| HEX | #3F455D |
| RGB | rgb(63, 69, 93) |
| HSL | hsl(228, 19%, 31%) |
| OKLCH | oklch(39.5% 0.041 273.5) |
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 #3F455D | 9.45:1 | AAA | Lc -96.1 | Preferred for body text |
| Black text on #3F455D | 2.22:1 | Fails | Lc 12.1 | Not readable |
| #3F455D text on white | 9.45:1 | AAA | Lc 91.9 | Preferred for body text |
| #3F455D text on black | 2.22:1 | Fails | Lc -10.5 | 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
#F4F5F8
oklch(97% 0.004 271.4)
-
Step 100
100
#E8E9F0
oklch(93.5% 0.009 279.7)
-
Step 200
200
#D5D9E5
oklch(88.6% 0.017 271.2)
-
Step 300
300
#BAC0D5
oklch(81% 0.03 273)
-
Step 400
400
#969FC0
oklch(70.7% 0.049 273.1)
-
Step 500
500
#7D87B1
oklch(63.1% 0.064 274)
-
Step 600
600
#66719C
oklch(55.7% 0.068 273)
-
Step 700
700
#555E86
oklch(49.1% 0.065 274)
-
Step 800
800
#454D6C
oklch(42.6% 0.053 272.9)
-
Step 900
900 (this color)
#3F455D
oklch(39.5% 0.041 273.5)
-
Step 950
950
#222633
oklch(27.1% 0.025 271.4)
#3F455D 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) | #3E475E | 0.006 |
| Deuteranopia (no green cones) | #3C455C | 0.005 |
| Tritanopia (no blue cones) | #374A4D | 0.038 |
| Achromatopsia (no color) | #464646 | 0.041 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F455D
#3F455D
oklch(39.5% 0.041 273.5)
- #4E462C
#4E462C
oklch(39.5% 0.042 93)
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 #3F455D, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.030
- Charcoal #264653 ΔE 0.040
- Charcoal Grey #3C4142 ΔE 0.046
- Dark Slate Gray #2F4F4F ΔE 0.050
- Onyx #343A40 ΔE 0.058
- Dark Blue Grey #1F3B4D ΔE 0.062
- YInMn Blue #415A77 ΔE 0.069
- Dark Teal #014D4E ΔE 0.070
Use #3F455D 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.