#3F3F8A
Closest named color: Dark Slate Blue (#483D8B). oklch(41% 0.122 279.6), rgb(63, 63, 138).
Aa
White text reads best on this color (9.17:1).
About this color
#3F3F8A is a dark, moderately saturated blue. In OKLCH its lightness is 41%, its chroma 0.122 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.015 away. White text reads best on it, at 9.17:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | moderately saturated (0.122) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.28:1 |
| White text | 9.17:1 |
Values
| HEX | #3F3F8A |
| RGB | rgb(63, 63, 138) |
| HSL | hsl(240, 37%, 39%) |
| OKLCH | oklch(41% 0.122 279.6) |
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 #3F3F8A | 9.17:1 | AAA | Lc -95.3 | Preferred for body text |
| Black text on #3F3F8A | 2.28:1 | Fails | Lc 13.1 | Not readable |
| #3F3F8A text on white | 9.17:1 | AAA | Lc 90.9 | Preferred for body text |
| #3F3F8A text on black | 2.28:1 | Fails | Lc -11.4 | 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
#F4F5FC
oklch(97.1% 0.009 279.7)
-
Step 100
100
#E7E9F8
oklch(93.7% 0.02 279.9)
-
Step 200
200
#D3D7F4
oklch(88.5% 0.04 279.3)
-
Step 300
300
#B7BCEF
oklch(80.9% 0.072 280.3)
-
Step 400
400
#9298E6
oklch(70.6% 0.114 279.7)
-
Step 500
500
#797DDF
oklch(63.1% 0.145 279.6)
-
Step 600
600
#6364CD
oklch(55.6% 0.159 279.5)
-
Step 700
700
#5252B1
oklch(49% 0.147 279.5)
-
Step 800
800 (this color)
#3F3F8A
oklch(41% 0.122 279.6)
-
Step 900
900
#383A72
oklch(37.7% 0.094 279.3)
-
Step 950
950
#212243
oklch(26.9% 0.061 280.2)
#3F3F8A 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) | #164B8D | 0.050 |
| Deuteranopia (no green cones) | #0A4588 | 0.053 |
| Tritanopia (no blue cones) | #1E505E | 0.106 |
| Achromatopsia (no color) | #484848 | 0.122 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F3F8A
#3F3F8A
oklch(41% 0.122 279.6)
- #564B00
#564B00
oklch(41.1% 0.085 99.6)
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 #3F3F8A, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.015
- Blueberry #464196 ΔE 0.023
- Cobalt #1E488F ΔE 0.042
- Twilight #4E518B ΔE 0.057
- Dusk Blue #26538D ΔE 0.058
- Light Navy #155084 ΔE 0.062
- Twilight Blue #0A437A ΔE 0.062
- Sapphire #2138AB ΔE 0.070
Use #3F3F8A 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.