Make it easier to discern which color is the active color in the color scheme editor.

The only indication is a dark gray fill in the triangle atop the selected color bucket that blends into the background. The other is white, which doesn't make it easily apparent which is active. Could this be blue, or outlined? I always have trouble discerning which color I'm editing, especially when they're similar colors, and it's a drag on efficiency.
It's a bit clearer for light mode users:
