#3F656D has no name of its own. This is the closest color that does — below the threshold most eyes can separate.
Built by rotating the hue in OKLCH, so every colour keeps the same lightness instead of drifting the way an HSL rotation does. Each one is named and clickable.
The colour directly opposite. Maximum contrast — good for a single accent against a dominant colour.
Neighbours on either side. Calm and cohesive, because nothing fights for attention.
Three colours evenly spaced around the wheel. Vivid but balanced.
The two colours either side of the opposite. Nearly the contrast of a complementary pair, with less tension.
Two complementary pairs. The richest scheme, and the easiest to overdo — let one colour lead.
One hue at several lightnesses. Reliable for interfaces, where hue changes read as meaning.
The same colour with lightness taken away.
The same colour with lightness added.
The same colour with the saturation drained out.
White text reads best, at 6.4:1.
6.38:1
3.29:1