#3F417C
Closest named color: Dark Slate Blue (#483D8B). oklch(40.4% 0.098 279.6), rgb(63, 65, 124).
Aa
White text reads best on this color (9.29:1).
About this color
#3F417C is a dark, moderately saturated blue. In OKLCH its lightness is 40%, its chroma 0.098 and its hue 280°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.032 away. White text reads best on it, at 9.29:1.
| Hue family | Blues |
| Lightness | dark (40%) |
| Chroma | moderately saturated (0.098) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.25:1 |
| White text | 9.29:1 |
Values
| HEX | #3F417C |
| RGB | rgb(63, 65, 124) |
| HSL | hsl(238, 33%, 37%) |
| OKLCH | oklch(40.4% 0.098 279.6) |
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 #3F417C | 9.29:1 | AAA | Lc -95.7 | Preferred for body text |
| Black text on #3F417C | 2.25:1 | Fails | Lc 12.6 | Not readable |
| #3F417C text on white | 9.29:1 | AAA | Lc 91.3 | Preferred for body text |
| #3F417C text on black | 2.25:1 | Fails | Lc -11.0 | 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
#F4F5FB
oklch(97.1% 0.008 278.6)
-
Step 100
100
#E7E9F5
oklch(93.6% 0.016 278.5)
-
Step 200
200
#D4D7EE
oklch(88.4% 0.032 279.8)
-
Step 300
300
#B8BDE6
oklch(80.8% 0.058 279.6)
-
Step 400
400
#959BD9
oklch(70.8% 0.091 279.5)
-
Step 500
500
#7C81CF
oklch(63.2% 0.117 279.7)
-
Step 600
600
#6569BC
oklch(55.6% 0.127 279.3)
-
Step 700
700
#5457A2
oklch(49.1% 0.118 279.4)
-
Step 800
800 (this color)
#3F417C
oklch(40.4% 0.098 279.6)
-
Step 900
900
#3A3C69
oklch(37.7% 0.076 280.1)
-
Step 950
950
#22243E
oklch(27.2% 0.048 279.3)
#3F417C 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) | #29497E | 0.034 |
| Deuteranopia (no green cones) | #24457B | 0.035 |
| Tritanopia (no blue cones) | #294D58 | 0.085 |
| Achromatopsia (no color) | #474747 | 0.098 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F417C
#3F417C
oklch(40.4% 0.098 279.6)
- #544900
#544900
oklch(40.4% 0.084 99.4)
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 #3F417C, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.032
- Blueberry #464196 ΔE 0.045
- Cobalt #1E488F ΔE 0.048
- Twilight Blue #0A437A ΔE 0.054
- Light Navy #155084 ΔE 0.056
- Twilight #4E518B ΔE 0.056
- Dusk Blue #26538D ΔE 0.057
- Dusk #4E5481 ΔE 0.062
Use #3F417C 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.