#3F4574
Closest named color: Dark Slate Blue (#483D8B). oklch(40.8% 0.079 276.8), rgb(63, 69, 116).
Aa
White text reads best on this color (9.07:1).
About this color
#3F4574 is a dark, moderately saturated blue. In OKLCH its lightness is 41%, its chroma 0.079 and its hue 277°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.049 away. White text reads best on it, at 9.07:1.
| Hue family | Blues |
| Lightness | dark (41%) |
| Chroma | moderately saturated (0.079) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.31:1 |
| White text | 9.07:1 |
Values
| HEX | #3F4574 |
| RGB | rgb(63, 69, 116) |
| HSL | hsl(233, 30%, 35%) |
| OKLCH | oklch(40.8% 0.079 276.8) |
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 #3F4574 | 9.07:1 | AAA | Lc -95.2 | Preferred for body text |
| Black text on #3F4574 | 2.31:1 | Fails | Lc 13.2 | Not readable |
| #3F4574 text on white | 9.07:1 | AAA | Lc 90.8 | Preferred for body text |
| #3F4574 text on black | 2.31:1 | Fails | Lc -11.5 | 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
#F4F5FA
oklch(97.1% 0.007 277.2)
-
Step 100
100
#E7E9F3
oklch(93.5% 0.014 277.1)
-
Step 200
200
#D4D8EA
oklch(88.5% 0.025 275.9)
-
Step 300
300
#B8BFDF
oklch(81% 0.046 275.6)
-
Step 400
400
#949DCF
oklch(70.7% 0.074 276.4)
-
Step 500
500
#7B84C2
oklch(63.1% 0.094 277)
-
Step 600
600
#646DAF
oklch(55.6% 0.103 276.6)
-
Step 700
700
#535B96
oklch(49.1% 0.095 276.5)
-
Step 800
800 (this color)
#3F4574
oklch(40.8% 0.079 276.8)
-
Step 900
900
#393E62
oklch(37.6% 0.062 277)
-
Step 950
950
#212539
oklch(27% 0.038 274.9)
#3F4574 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) | #344B76 | 0.021 |
| Deuteranopia (no green cones) | #304773 | 0.021 |
| Tritanopia (no blue cones) | #2D4F57 | 0.070 |
| Achromatopsia (no color) | #494949 | 0.079 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F4574
#3F4574
oklch(40.8% 0.079 276.8)
- #56490A
#56490A
oklch(40.7% 0.079 96.4)
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 #3F4574, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.049
- Light Navy #155084 ΔE 0.052
- Dusk #4E5481 ΔE 0.053
- Twilight #4E518B ΔE 0.054
- Dark Grey Blue #29465B ΔE 0.055
- Twilight Blue #0A437A ΔE 0.055
- Dusk Blue #26538D ΔE 0.056
- Cobalt #1E488F ΔE 0.056
Use #3F4574 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.