#3F455E
Closest named color: Dark Grey Blue (#29465B). oklch(39.6% 0.043 273.8), rgb(63, 69, 94).
Aa
White text reads best on this color (9.44:1).
About this color
#3F455E is a dark, muted blue. In OKLCH its lightness is 40%, its chroma 0.043 and its hue 274°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.031 away. White text reads best on it, at 9.44:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | muted (0.043) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 2.22:1 |
| White text | 9.44:1 |
Values
| HEX | #3F455E |
| RGB | rgb(63, 69, 94) |
| HSL | hsl(228, 20%, 31%) |
| OKLCH | oklch(39.6% 0.043 273.8) |
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 #3F455E | 9.44:1 | AAA | Lc -96.1 | Preferred for body text |
| Black text on #3F455E | 2.22:1 | Fails | Lc 12.1 | Not readable |
| #3F455E text on white | 9.44:1 | AAA | Lc 91.8 | Preferred for body text |
| #3F455E text on black | 2.22:1 | Fails | Lc -10.6 | 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
#BAC0D6
oklch(81% 0.032 273.6)
-
Step 400
400
#969FC2
oklch(70.7% 0.052 273.7)
-
Step 500
500
#7D87B2
oklch(63.1% 0.066 274.2)
-
Step 600
600
#66709E
oklch(55.5% 0.073 274.4)
-
Step 700
700
#555E87
oklch(49.2% 0.067 274.2)
-
Step 800
800
#454D6E
oklch(42.7% 0.056 273.4)
-
Step 900
900 (this color)
#3F455E
oklch(39.6% 0.043 273.8)
-
Step 950
950
#222634
oklch(27.1% 0.027 272.1)
#3F455E 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) | #3D475F | 0.006 |
| Deuteranopia (no green cones) | #3B455D | 0.006 |
| Tritanopia (no blue cones) | #374A4E | 0.038 |
| Achromatopsia (no color) | #464646 | 0.043 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F455E
#3F455E
oklch(39.6% 0.043 273.8)
- #4E462B
#4E462B
oklch(39.5% 0.043 93.5)
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 #3F455E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.031
- Charcoal #264653 ΔE 0.041
- Charcoal Grey #3C4142 ΔE 0.047
- Dark Slate Gray #2F4F4F ΔE 0.052
- Onyx #343A40 ΔE 0.060
- Dark Blue Grey #1F3B4D ΔE 0.063
- YInMn Blue #415A77 ΔE 0.068
- Dark Teal #014D4E ΔE 0.071
Use #3F455E 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.