#3F4978
Closest named color: Dusk (#4E5481). oklch(41.9% 0.079 273.4), rgb(63, 73, 120).
Aa
White text reads best on this color (8.62:1).
About this color
#3F4978 is a dark, moderately saturated blue. In OKLCH its lightness is 42%, its chroma 0.079 and its hue 273°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk (#4E5481), ΔE 0.042 away. White text reads best on it, at 8.62:1.
| Hue family | Blues |
| Lightness | dark (42%) |
| Chroma | moderately saturated (0.079) |
| Temperature | cool |
| Nearest name | Dusk (#4E5481) |
| Black text | 2.43:1 |
| White text | 8.62:1 |
Values
| HEX | #3F4978 |
| RGB | rgb(63, 73, 120) |
| HSL | hsl(229, 31%, 36%) |
| OKLCH | oklch(41.9% 0.079 273.4) |
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 #3F4978 | 8.62:1 | AAA | Lc -94.0 | Preferred for body text |
| Black text on #3F4978 | 2.43:1 | Fails | Lc 14.5 | Not readable |
| #3F4978 text on white | 8.62:1 | AAA | Lc 89.5 | Fine for body text |
| #3F4978 text on black | 2.43:1 | Fails | Lc -12.7 | 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 800.
-
Step 50
50
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E7E9F3
oklch(93.5% 0.014 277.1)
-
Step 200
200
#D3D8EB
oklch(88.4% 0.027 274.1)
-
Step 300
300
#B7BFDF
oklch(80.9% 0.046 274.3)
-
Step 400
400
#919ED0
oklch(70.7% 0.075 273.1)
-
Step 500
500
#7785C3
oklch(63.1% 0.095 273.7)
-
Step 600
600
#606EB0
oklch(55.6% 0.104 273.5)
-
Step 700
700
#4F5C97
oklch(49.1% 0.096 273)
-
Step 800
800 (this color)
#3F4978
oklch(41.9% 0.079 273.4)
-
Step 900
900
#373F62
oklch(37.7% 0.061 273.3)
-
Step 950
950
#20253A
oklch(27% 0.04 273.2)
#3F4978 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) | #384E7A | 0.016 |
| Deuteranopia (no green cones) | #334A77 | 0.016 |
| Tritanopia (no blue cones) | #2B535A | 0.072 |
| Achromatopsia (no color) | #4C4C4C | 0.079 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F4978
#3F4978
oklch(41.9% 0.079 273.4)
- #5B4B0D
#5B4B0D
oklch(41.8% 0.079 93.4)
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 #3F4978, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk #4E5481 ΔE 0.042
- Twilight #4E518B ΔE 0.044
- Light Navy #155084 ΔE 0.045
- Dusk Blue #26538D ΔE 0.046
- Dark Slate Blue #483D8B ΔE 0.051
- Light Navy Blue #2E5A88 ΔE 0.052
- YInMn Blue #415A77 ΔE 0.053
- Cobalt #1E488F ΔE 0.053
Use #3F4978 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.