#3F4258
Closest named color: Dark Grey Blue (#29465B). oklch(38.6% 0.038 278.4), rgb(63, 66, 88).
Aa
White text reads best on this color (9.85:1).
About this color
#3F4258 is a dark, muted blue. In OKLCH its lightness is 39%, its chroma 0.038 and its hue 278°. 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 9.85:1.
| Hue family | Blues |
| Lightness | dark (39%) |
| Chroma | muted (0.038) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 2.13:1 |
| White text | 9.85:1 |
Values
| HEX | #3F4258 |
| RGB | rgb(63, 66, 88) |
| HSL | hsl(233, 17%, 30%) |
| OKLCH | oklch(38.6% 0.038 278.4) |
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 #3F4258 | 9.85:1 | AAA | Lc -97.0 | Preferred for body text |
| Black text on #3F4258 | 2.13:1 | Fails | Lc 11.1 | Not readable |
| #3F4258 text on white | 9.85:1 | AAA | Lc 92.9 | Preferred for body text |
| #3F4258 text on black | 2.13:1 | Fails | Lc -9.6 | 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
#F5F5F8
oklch(97.1% 0.004 286.3)
-
Step 100
100
#E8E9EF
oklch(93.5% 0.008 278.6)
-
Step 200
200
#D6D8E4
oklch(88.4% 0.017 278.5)
-
Step 300
300
#BCBFD3
oklch(80.9% 0.028 279)
-
Step 400
400
#9A9EBD
oklch(70.7% 0.045 279.4)
-
Step 500
500
#8186AD
oklch(63% 0.059 278.9)
-
Step 600
600
#6B7098
oklch(55.7% 0.062 278.6)
-
Step 700
700
#595E82
oklch(49.2% 0.058 277.9)
-
Step 800
800
#494C69
oklch(42.6% 0.048 279.6)
-
Step 900
900 (this color)
#3F4258
oklch(38.6% 0.038 278.4)
-
Step 950
950
#242532
oklch(26.9% 0.024 281.2)
#3F4258 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) | #3C4459 | 0.007 |
| Deuteranopia (no green cones) | #3A4257 | 0.008 |
| Tritanopia (no blue cones) | #39464A | 0.033 |
| Achromatopsia (no color) | #434343 | 0.038 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F4258
#3F4258
oklch(38.6% 0.038 278.4)
- #49442D
#49442D
oklch(38.5% 0.037 97.4)
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 #3F4258, 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 0.038
- Charcoal Grey #3C4142 ΔE 0.038
- Onyx #343A40 ΔE 0.049
- Dark Slate Gray #2F4F4F ΔE 0.053
- Dark Blue Grey #1F3B4D ΔE 0.056
- Prussian Blue #1D3557 ΔE 0.068
- Dark Teal #014D4E ΔE 0.070
Use #3F4258 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.