lerath666
Super Freak
Yeah they went back and forth. My personal theory is that they changed as he abandoned himself to the dark side and then when he calmed down they changed back. I also think that once a person goes completely to the dark side they stay that way permanently such as with Maul. On the other hand if you don't completely let yourself be immersed in the dark side then you don't have them like with Dooku. And I think Palpatine had them but was able to hide them or make them go away by his mastery of the dark side.
that's the accepted idea in the EU AFAIK. GO read SW Legacy. When cade draws on the dark sidee, his eyes burn the sith colors. when he calms down, they go away. Darth Kryat is drawing on it nonstop, and his eye is constantly in sith-mode.