#3F4783
Closest named color: Dark Slate Blue (#483D8B). oklch(42.2% 0.099 275.6), rgb(63, 71, 131).
Aa
White text reads best on this color (8.60:1).
About this color
#3F4783 is a dark, moderately saturated blue. In OKLCH its lightness is 42%, its chroma 0.099 and its hue 276°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Slate Blue (#483D8B), ΔE 0.033 away. White text reads best on it, at 8.60:1.
| Hue family | Blues |
| Lightness | dark (42%) |
| Chroma | moderately saturated (0.099) |
| Temperature | cool |
| Nearest name | Dark Slate Blue (#483D8B) |
| Black text | 2.44:1 |
| White text | 8.60:1 |
Values
| HEX | #3F4783 |
| RGB | rgb(63, 71, 131) |
| HSL | hsl(233, 35%, 38%) |
| OKLCH | oklch(42.2% 0.099 275.6) |
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 #3F4783 | 8.60:1 | AAA | Lc -93.9 | Preferred for body text |
| Black text on #3F4783 | 2.44:1 | Fails | Lc 14.6 | Not readable |
| #3F4783 text on white | 8.60:1 | AAA | Lc 89.4 | Fine for body text |
| #3F4783 text on black | 2.44:1 | Fails | Lc -12.8 | 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
#F4F5FB
oklch(97.1% 0.008 278.6)
-
Step 100
100
#E6E9F5
oklch(93.5% 0.016 274.8)
-
Step 200
200
#D3D8EF
oklch(88.5% 0.032 276)
-
Step 300
300
#B6BEE7
oklch(80.9% 0.059 276.4)
-
Step 400
400
#909CDB
oklch(70.7% 0.093 275.5)
-
Step 500
500
#7682D1
oklch(63.1% 0.119 275.9)
-
Step 600
600
#5F6ABE
oklch(55.5% 0.13 275.7)
-
Step 700
700
#4F58A4
oklch(49.1% 0.121 275.9)
-
Step 800
800 (this color)
#3F4783
oklch(42.2% 0.099 275.6)
-
Step 900
900
#363D6A
oklch(37.6% 0.077 275.4)
-
Step 950
950
#20243E
oklch(27% 0.049 276)
#3F4783 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) | #2E4F85 | 0.029 |
| Deuteranopia (no green cones) | #274982 | 0.030 |
| Tritanopia (no blue cones) | #23545E | 0.089 |
| Achromatopsia (no color) | #4C4C4C | 0.100 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #3F4783
#3F4783
oklch(42.2% 0.099 275.6)
- #5C4C00
#5C4C00
oklch(42% 0.086 95.1)
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 #3F4783, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Slate Blue #483D8B ΔE 0.033
- Blueberry #464196 ΔE 0.038
- Twilight #4E518B ΔE 0.039
- Cobalt #1E488F ΔE 0.041
- Dusk Blue #26538D ΔE 0.041
- Light Navy #155084 ΔE 0.046
- Dusk #4E5481 ΔE 0.047
- Light Navy Blue #2E5A88 ΔE 0.055
Use #3F4783 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.