im usually using 2xRed 1xGreen and 1xblue+yellow perks (mostly just single blue skill and 2 perks). With new mutations, i went into 3xRed 1xblue+yellow, and bonus skills green with Euphoria...
This way, i have both fast and heavy attacks 3 skills into each, then three special red skills for adrenaline effects, and all those important high level alchemy skills..
