#3F507E
Closest named color: Dusk (#4E5481). oklch(43.9% 0.079 267.7), rgb(63, 80, 126).
Aa
White text reads best on this color (7.89:1).
About this color
#3F507E is a dark, moderately saturated blue. In OKLCH its lightness is 44%, its chroma 0.079 and its hue 268°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk (#4E5481), ΔE 0.026 away. White text reads best on it, at 7.89:1.
| Hue family | Blues |
| Lightness | dark (44%) |
| Chroma | moderately saturated (0.079) |
| Temperature | cool |
| Nearest name | Dusk (#4E5481) |
| Black text | 2.66:1 |
| White text | 7.89:1 |
Values
| HEX | #3F507E |
| RGB | rgb(63, 80, 126) |
| HSL | hsl(224, 33%, 37%) |
| OKLCH | oklch(43.9% 0.079 267.7) |
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 #3F507E | 7.89:1 | AAA | Lc -92.0 | Preferred for body text |
| Black text on #3F507E | 2.66:1 | Fails | Lc 16.7 | Dividers and decoration only |
| #3F507E text on white | 7.89:1 | AAA | Lc 87.3 | Fine for body text |
| #3F507E text on black | 2.66:1 | Fails | Lc -14.8 | 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
#F3F5FA
oklch(97% 0.007 268.5)
-
Step 100
100
#E6EAF3
oklch(93.7% 0.013 266.7)
-
Step 200
200
#D2D9EB
oklch(88.5% 0.026 268.8)
-
Step 300
300
#B3C0DF
oklch(80.8% 0.046 267.4)
-
Step 400
400
#8C9FD0
oklch(70.6% 0.075 268)
-
Step 500
500
#7087C3
oklch(63% 0.095 267.6)
-
Step 600
600
#5970B0
oklch(55.6% 0.104 268)
-
Step 700
700
#495E97
oklch(49.2% 0.095 267.5)
-
Step 800
800 (this color)
#3F507E
oklch(43.9% 0.079 267.7)
-
Step 900
900
#334063
oklch(37.7% 0.063 267.8)
-
Step 950
950
#1E263A
oklch(27.1% 0.039 267.1)
#3F507E 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) | #3F5480 | 0.012 |
| Deuteranopia (no green cones) | #384F7D | 0.010 |
| Tritanopia (no blue cones) | #265A61 | 0.071 |
| Achromatopsia (no color) | #515151 | 0.079 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F507E
#3F507E
oklch(43.9% 0.079 267.7)
- #654F15
#654F15
oklch(43.9% 0.079 87.1)
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 #3F507E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk #4E5481 ΔE 0.026
- Twilight #4E518B ΔE 0.031
- Light Navy Blue #2E5A88 ΔE 0.033
- Dusk Blue #26538D ΔE 0.034
- YInMn Blue #415A77 ΔE 0.036
- Denim Blue #3B5B92 ΔE 0.041
- Light Navy #155084 ΔE 0.041
- Dusty Grape #545775 ΔE 0.043
Use #3F507E 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.