I'd prefer the current Toggle Colour function over on that also toggled the marked flag. The reason being that I sometimes want to find what playlists an item is in (the propogation up the tree is essential for this - please consider re-adding this, even if it needs a user action to compute it), and it would be confusing if the other marked tracks got in the way. And I don't want to have to clear marks for this. If I want marked tracks to be coloured, it's dead easy to search for marked tracks, select them, and colour them.
One thing that would be nice would be to distinguish playlists that are coloured from those that merely inherit a colour from one or more children. Bold text, perhaps?
And another colour (purple?) for nodes that are both marked and modified.
Anyway, don't let any of this slow down the release we're all waiting for. They're just tweaks that can wait for a subsequent version.
I'm really looking forward to a new JEmplode so that I can share my playlist stylesheet.