#3F4571
Closest named color: Dark Grey Blue (#29465B). oklch(40.6% 0.074 276.7), rgb(63, 69, 113).
Aa
White text reads best on this color (9.12:1).
About this color
#3F4571 is a dark, moderately saturated blue. In OKLCH its lightness is 41%, its chroma 0.074 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Grey Blue (#29465B), ΔE 0.051 away. White text reads best on it, at 9.12:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | moderately saturated (0.074) |
| Temperature | cool |
| Nearest name | Dark Grey Blue (#29465B) |
| Black text | 2.30:1 |
| White text | 9.12:1 |
Values
| HEX | #3F4571 |
| RGB | rgb(63, 69, 113) |
| HSL | hsl(233, 28%, 35%) |
| OKLCH | oklch(40.6% 0.074 276.7) |
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 #3F4571 | 9.12:1 | AAA | Lc -95.3 | Preferred for body text |
| Black text on #3F4571 | 2.30:1 | Fails | Lc 13.0 | Not readable |
| #3F4571 text on white | 9.12:1 | AAA | Lc 90.9 | Preferred for body text |
| #3F4571 text on black | 2.30:1 | Fails | Lc -11.4 | 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
#E7E9F2
oklch(93.5% 0.012 276.1)
-
Step 200
200
#D5D8E9
oklch(88.5% 0.023 277.9)
-
Step 300
300
#B9BFDD
oklch(81% 0.043 276.5)
-
Step 400
400
#959DCC
oklch(70.7% 0.069 277)
-
Step 500
500
#7B85BF
oklch(63.2% 0.088 276.1)
-
Step 600
600
#656EAB
oklch(55.7% 0.095 276.5)
-
Step 700
700
#545B93
oklch(49.1% 0.09 277.1)
-
Step 800
800 (this color)
#3F4571
oklch(40.6% 0.074 276.7)
-
Step 900
900
#3A3F60
oklch(37.8% 0.057 276.7)
-
Step 950
950
#222538
oklch(27.1% 0.036 276.8)
#3F4571 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) | #364A73 | 0.018 |
| Deuteranopia (no green cones) | #324670 | 0.018 |
| Tritanopia (no blue cones) | #2F4E55 | 0.066 |
| Achromatopsia (no color) | #484848 | 0.074 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F4571
#3F4571
oklch(40.6% 0.074 276.7)
- #554911
#554911
oklch(40.6% 0.074 96.6)
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 #3F4571, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Grey Blue #29465B ΔE 0.051
- Light Navy #155084 ΔE 0.054
- Dark Slate Blue #483D8B ΔE 0.054
- Dusk #4E5481 ΔE 0.055
- Twilight Blue #0A437A ΔE 0.056
- Twilight #4E518B ΔE 0.057
- Dusk Blue #26538D ΔE 0.059
- Cobalt #1E488F ΔE 0.060
Use #3F4571 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.