#3F3374
Closest named color: Dark Slate Blue (#483D8B). oklch(37% 0.107 288.5), rgb(63, 51, 116).
Aa
White text reads best on this color (10.84:1).
About this color
#3F3374 is a dark, moderately saturated purple. In OKLCH its lightness is 37%, its chroma 0.107 and its hue 289°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.048 away. White text reads best on it, at 10.84:1.
| Hue family | Purples |
| Lightness | dark (37%) |
| Chroma | moderately saturated (0.107) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 1.93:1 |
| White text | 10.84:1 |
Values
| HEX | #3F3374 |
| RGB | rgb(63, 51, 116) |
| HSL | hsl(251, 39%, 33%) |
| OKLCH | oklch(37% 0.107 288.5) |
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 #3F3374 | 10.84:1 | AAA | Lc -98.8 | Preferred for body text |
| Black text on #3F3374 | 1.93:1 | Fails | Lc 9.0 | Not readable |
| #3F3374 text on white | 10.84:1 | AAA | Lc 94.9 | Preferred for body text |
| #3F3374 text on black | 1.93:1 | Fails | Lc -7.7 | 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
#F5F4FC
oklch(97% 0.011 292)
-
Step 100
100
#E9E8F9
oklch(93.7% 0.023 288.7)
-
Step 200
200
#D7D5F6
oklch(88.5% 0.045 288.2)
-
Step 300
300
#BEB9F2
oklch(80.9% 0.08 288.5)
-
Step 400
400
#9E92EC
oklch(70.7% 0.13 288.7)
-
Step 500
500
#8875E5
oklch(63.2% 0.163 288.6)
-
Step 600
600
#735AD3
oklch(55.6% 0.179 288.7)
-
Step 700
700
#6149B7
oklch(49.1% 0.166 288.8)
-
Step 800
800
#4F3D94
oklch(42.8% 0.137 288.8)
-
Step 900
900 (this color)
#3F3374
oklch(37% 0.107 288.5)
-
Step 950
950
#262045
oklch(27.1% 0.067 288.6)
#3F3374 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) | #133F76 | 0.059 |
| Deuteranopia (no green cones) | #143C73 | 0.058 |
| Tritanopia (no blue cones) | #2F414E | 0.089 |
| Achromatopsia (no color) | #3D3D3D | 0.108 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F3374
#3F3374
oklch(37% 0.107 288.5)
- #444200
#444200
oklch(36.9% 0.079 107.8)
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 #3F3374, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.048
- Blueberry #464196 ΔE 0.066
- Twilight Blue #0A437A ΔE 0.067
- Marine Blue #01386A ΔE 0.072
- Prussian Blue #1D3557 ΔE 0.074
- Cobalt #1E488F ΔE 0.075
- Dark Grey Blue #29465B ΔE 0.083
- Indigo #4B0082 ΔE 0.085
Use #3F3374 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.