#3F537E
Closest named color: Dusk (#4E5481). oklch(44.6% 0.075 264.5), rgb(63, 83, 126).
Aa
White text reads best on this color (7.63:1).
About this color
#3F537E is a dark, moderately saturated blue. In OKLCH its lightness is 45%, its chroma 0.075 and its hue 265°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk (#4E5481), ΔE 0.022 away. White text reads best on it, at 7.63:1.
| Hue family | Blues |
| Lightness | dark (45%) |
| Chroma | moderately saturated (0.075) |
| Temperature | cool |
| Nearest name | Dusk (#4E5481) |
| Black text | 2.74:1 |
| White text | 7.63:1 |
Values
| HEX | #3F537E |
| RGB | rgb(63, 83, 126) |
| HSL | hsl(221, 33%, 37%) |
| OKLCH | oklch(44.6% 0.075 264.5) |
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 #3F537E | 7.63:1 | AAA | Lc -91.2 | Preferred for body text |
| Black text on #3F537E | 2.74:1 | Fails | Lc 17.6 | Dividers and decoration only |
| #3F537E text on white | 7.63:1 | AAA | Lc 86.5 | Fine for body text |
| #3F537E text on black | 2.74:1 | Fails | Lc -15.6 | Dividers and decoration only |
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
#D1D9EA
oklch(88.4% 0.025 265.6)
-
Step 300
300
#B3C1DE
oklch(81% 0.044 264.9)
-
Step 400
400
#8BA0CD
oklch(70.6% 0.07 265.2)
-
Step 500
500
#6E89C0
oklch(63.2% 0.089 263.9)
-
Step 600
600
#5672AD
oklch(55.6% 0.098 264.1)
-
Step 700
700
#475F94
oklch(49.1% 0.09 264.8)
-
Step 800
800 (this color)
#3F537E
oklch(44.6% 0.075 264.5)
-
Step 900
900
#324161
oklch(37.7% 0.059 264.6)
-
Step 950
950
#1D2639
oklch(27% 0.038 264.5)
#3F537E 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) | #435780 | 0.014 |
| Deuteranopia (no green cones) | #3C517D | 0.008 |
| Tritanopia (no blue cones) | #255C62 | 0.068 |
| Achromatopsia (no color) | #535353 | 0.075 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F537E
#3F537E
oklch(44.6% 0.075 264.5)
- #67501C
#67501C
oklch(44.5% 0.075 84.6)
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 #3F537E, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk #4E5481 ΔE 0.022
- Light Navy Blue #2E5A88 ΔE 0.027
- YInMn Blue #415A77 ΔE 0.027
- Twilight #4E518B ΔE 0.032
- Dusk Blue #26538D ΔE 0.035
- Denim Blue #3B5B92 ΔE 0.036
- Dusty Grape #545775 ΔE 0.037
- Light Navy #155084 ΔE 0.044
Use #3F537E 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.