#3B3791
Closest named color: Dark Slate Blue (#483D8B). oklch(39.7% 0.144 279.6), rgb(59, 55, 145).
Aa
White text reads best on this color (9.80:1).
About this color
#3B3791 is a dark, vivid blue. In OKLCH its lightness is 40%, its chroma 0.144 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.030 away. White text reads best on it, at 9.80:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | vivid (0.144) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.14:1 |
| White text | 9.80:1 |
Values
| HEX | #3B3791 |
| RGB | rgb(59, 55, 145) |
| HSL | hsl(243, 45%, 39%) |
| OKLCH | oklch(39.7% 0.144 279.6) |
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 #3B3791 | 9.80:1 | AAA | Lc -96.6 | Preferred for body text |
| Black text on #3B3791 | 2.14:1 | Fails | Lc 11.6 | Not readable |
| #3B3791 text on white | 9.80:1 | AAA | Lc 92.3 | Preferred for body text |
| #3B3791 text on black | 2.14:1 | Fails | Lc -10.1 | 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
#F3F5FF
oklch(97.2% 0.013 277.1)
-
Step 100
100
#E5E8FF
oklch(93.6% 0.031 279.9)
-
Step 200
200
#D1D6FF
oklch(88.5% 0.057 279.7)
-
Step 300
300
#B3BAFF
oklch(80.8% 0.098 279.5)
-
Step 400
400
#8E93FF
oklch(70.6% 0.156 279.6)
-
Step 500
500
#7573FF
oklch(63% 0.202 279.5)
-
Step 600
600
#6150F9
oklch(55.6% 0.24 279.7)
-
Step 700
700
#513FD9
oklch(49.1% 0.223 279.6)
-
Step 800
800
#4236AF
oklch(42.7% 0.184 279.7)
-
Step 900
900 (this color)
#3B3791
oklch(39.7% 0.144 279.6)
-
Step 950
950
#1F1E51
oklch(27% 0.091 279.3)
#3B3791 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) | #004794 | 0.059 |
| Deuteranopia (no green cones) | #00408F | 0.055 |
| Tritanopia (no blue cones) | #044D5E | 0.125 |
| Achromatopsia (no color) | #444444 | 0.144 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3B3791
#3B3791
oklch(39.7% 0.144 279.6)
- #524700
#524700
oklch(39.7% 0.082 99.1)
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 #3B3791, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.030
- Blueberry #464196 ΔE 0.033
- Cobalt #1E488F ΔE 0.051
- Sapphire #2138AB ΔE 0.054
- Twilight Blue #0A437A ΔE 0.070
- Indigo Blue #3A18B1 ΔE 0.071
- Imperial Purple #480CA8 ΔE 0.073
- Dusk Blue #26538D ΔE 0.077
Use #3B3791 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.