#3F557F
Closest named color: Dusk (#4E5481). oklch(45.1% 0.074 262.6), rgb(63, 85, 127).
Aa
White text reads best on this color (7.45:1).
About this color
#3F557F is a medium-dark, moderately saturated blue. In OKLCH its lightness is 45%, its chroma 0.074 and its hue 263°. Its hue sits on the cool side of the wheel. The nearest named color is Dusk (#4E5481), ΔE 0.021 away. White text reads best on it, at 7.45:1.
| Hue family | Blues |
| Lightness | medium-dark (45%) |
| Chroma | moderately saturated (0.074) |
| Temperature | cool |
| Nearest name | Dusk (#4E5481) |
| Black text | 2.81:1 |
| White text | 7.45:1 |
Values
| HEX | #3F557F |
| RGB | rgb(63, 85, 127) |
| HSL | hsl(219, 34%, 37%) |
| OKLCH | oklch(45.1% 0.074 262.6) |
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 #3F557F | 7.45:1 | AAA | Lc -90.7 | Preferred for body text |
| Black text on #3F557F | 2.81:1 | Fails | Lc 18.2 | Dividers and decoration only |
| #3F557F text on white | 7.45:1 | AAA | Lc 85.8 | Fine for body text |
| #3F557F text on black | 2.81:1 | Fails | Lc -16.2 | 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
#F3F5F9
oklch(97% 0.006 264.5)
-
Step 100
100
#E5EAF3
oklch(93.6% 0.013 262.4)
-
Step 200
200
#D1DAEA
oklch(88.6% 0.024 262.1)
-
Step 300
300
#B2C1DE
oklch(80.9% 0.044 263.6)
-
Step 400
400
#8AA1CD
oklch(70.7% 0.07 263.2)
-
Step 500
500
#6C89C0
oklch(63% 0.09 262.7)
-
Step 600
600
#5472AC
oklch(55.5% 0.097 262.8)
-
Step 700
700
#456094
oklch(49.2% 0.09 262.7)
-
Step 800
800 (this color)
#3F557F
oklch(45.1% 0.074 262.6)
-
Step 900
900
#314161
oklch(37.7% 0.059 263.5)
-
Step 950
950
#1D2639
oklch(27% 0.038 264.5)
#3F557F 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) | #455881 | 0.013 |
| Deuteranopia (no green cones) | #3E527E | 0.009 |
| Tritanopia (no blue cones) | #245E64 | 0.067 |
| Achromatopsia (no color) | #555555 | 0.074 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F557F
#3F557F
oklch(45.1% 0.074 262.6)
- #6A511F
#6A511F
oklch(45.1% 0.074 82)
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 #3F557F, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dusk #4E5481 ΔE 0.021
- YInMn Blue #415A77 ΔE 0.023
- Light Navy Blue #2E5A88 ΔE 0.024
- Denim Blue #3B5B92 ΔE 0.032
- Twilight #4E518B ΔE 0.033
- Dusty Grape #545775 ΔE 0.035
- Dusk Blue #26538D ΔE 0.036
- Denim #3B638C ΔE 0.042
Use #3F557F 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.