I think it would be nice to have the auto-coloring feature for non-snapped windows too, based on the active window. It would be nice especially when using tiling scripts, and I think it would also offer a better UX by not forcing to snap windows to the top to see the effect (while it is not an issue when using maximized or large windows, it could be a bit annoying to snap some smaller window to the top).
it is supported with latest master