#3F4B71
Closest named color: Dusk (#4E5481). oklch(42% 0.065 270), rgb(63, 75, 113).
Aa
White text reads best on this color (8.54:1).
About this color
#3F4B71 is a dark, muted blue. In OKLCH its lightness is 42%, its chroma 0.065 and its hue 270°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk (#4E5481), ΔE 0.043 away. White text reads best on it, at 8.54:1.
| Hue family | Blues |
| Lightness | dark (42%) |
| Chroma | muted (0.065) |
| Temperature | cool |
| Nearest name | Dusk (#4E5481) |
| Black text | 2.45:1 |
| White text | 8.54:1 |
Values
| HEX | #3F4B71 |
| RGB | rgb(63, 75, 113) |
| HSL | hsl(226, 28%, 35%) |
| OKLCH | oklch(42% 0.065 270) |
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 #3F4B71 | 8.54:1 | AAA | Lc -93.9 | Preferred for body text |
| Black text on #3F4B71 | 2.45:1 | Fails | Lc 14.6 | Not readable |
| #3F4B71 text on white | 8.54:1 | AAA | Lc 89.3 | Fine for body text |
| #3F4B71 text on black | 2.45:1 | Fails | Lc -12.9 | 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
#F4F5F9
oklch(97.1% 0.005 275)
-
Step 100
100
#E7EAF2
oklch(93.7% 0.011 269.5)
-
Step 200
200
#D3D9E8
oklch(88.5% 0.022 268.4)
-
Step 300
300
#B7C0DA
oklch(80.9% 0.038 270.4)
-
Step 400
400
#929FC8
oklch(70.7% 0.062 271)
-
Step 500
500
#7787B9
oklch(63% 0.078 270.4)
-
Step 600
600
#6071A6
oklch(55.7% 0.085 269.9)
-
Step 700
700
#4F5E8E
oklch(49.1% 0.079 270.1)
-
Step 800
800 (this color)
#3F4B71
oklch(42% 0.065 270)
-
Step 900
900
#37405D
oklch(37.6% 0.051 270.6)
-
Step 950
950
#202636
oklch(27% 0.031 268.4)
#3F4B71 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) | #3E4F73 | 0.012 |
| Deuteranopia (no green cones) | #394A70 | 0.009 |
| Tritanopia (no blue cones) | #2E5359 | 0.059 |
| Achromatopsia (no color) | #4C4C4C | 0.066 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F4B71
#3F4B71
oklch(42% 0.065 270)
- #5B4B1F
#5B4B1F
oklch(41.9% 0.065 89.3)
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 #3F4B71, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk #4E5481 ΔE 0.043
- YInMn Blue #415A77 ΔE 0.045
- Light Navy #155084 ΔE 0.049
- Dusty Grape #545775 ΔE 0.050
- Dark Grey Blue #29465B ΔE 0.051
- Twilight #4E518B ΔE 0.051
- Dusk Blue #26538D ΔE 0.052
- Light Navy Blue #2E5A88 ΔE 0.052
Use #3F4B71 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.