Complex sentence: The Veronicas were Kim Possible fans and decided to redo "4Ever" as a promotional video for the episode, which contained clips of Drakken and Shego and The Veronicas dressed in green and black, Shego's signature colors.
Split into simpler sentences: The Veronicas were Kim Possible fans and decided to redo "4Ever" as a promotional video for the episode. The video contained clips of Drakken and Shego, and The Veronicas dressed in green and black, Shego's signature colors.