#3F4478
Closest named color: Dark Slate Blue (#483D8B). oklch(40.8% 0.087 277.7), rgb(63, 68, 120).
Aa
White text reads best on this color (9.09:1).
About this color
#3F4478 is a dark, moderately saturated blue. In OKLCH its lightness is 41%, its chroma 0.087 and its hue 278°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.041 away. White text reads best on it, at 9.09:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | moderately saturated (0.087) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.30:1 |
| White text | 9.09:1 |
Values
| HEX | #3F4478 |
| RGB | rgb(63, 68, 120) |
| HSL | hsl(235, 31%, 36%) |
| OKLCH | oklch(40.8% 0.087 277.7) |
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 #3F4478 | 9.09:1 | AAA | Lc -95.2 | Preferred for body text |
| Black text on #3F4478 | 2.30:1 | Fails | Lc 13.2 | Not readable |
| #3F4478 text on white | 9.09:1 | AAA | Lc 90.8 | Preferred for body text |
| #3F4478 text on black | 2.30:1 | Fails | Lc -11.5 | 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 800.
-
Step 50
50
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E7E9F4
oklch(93.6% 0.015 277.8)
-
Step 200
200
#D4D8EC
oklch(88.5% 0.028 276.8)
-
Step 300
300
#B8BEE2
oklch(80.9% 0.051 277.7)
-
Step 400
400
#949CD3
oklch(70.7% 0.081 277.7)
-
Step 500
500
#7A83C8
oklch(63.1% 0.104 277.3)
-
Step 600
600
#646BB4
oklch(55.5% 0.113 277.9)
-
Step 700
700
#53599B
oklch(49% 0.105 277.8)
-
Step 800
800 (this color)
#3F4478
oklch(40.8% 0.087 277.7)
-
Step 900
900
#393E65
oklch(37.8% 0.067 277.1)
-
Step 950
950
#21243B
oklch(26.9% 0.043 277.4)
#3F4478 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) | #304B7A | 0.026 |
| Deuteranopia (no green cones) | #2C4677 | 0.026 |
| Tritanopia (no blue cones) | #2B4F58 | 0.077 |
| Achromatopsia (no color) | #484848 | 0.087 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F4478
#3F4478
oklch(40.8% 0.087 277.7)
- #564900
#564900
oklch(40.6% 0.084 97.5)
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 #3F4478, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.041
- Light Navy #155084 ΔE 0.051
- Cobalt #1E488F ΔE 0.051
- Twilight #4E518B ΔE 0.052
- Blueberry #464196 ΔE 0.053
- Dusk Blue #26538D ΔE 0.054
- Dusk #4E5481 ΔE 0.054
- Twilight Blue #0A437A ΔE 0.054
Use #3F4478 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.