Kill your Sim, and before the Grim Reaper takes him or her away, get your husband or wife to plead with him. He will say " I'm generous today, so I will spare your Sim", then bring him or her back to life. That Sim will now be green but will live a normal life. Note: If you do not want them to be a zombie, enable the move_objects on code and delete him or her. After that, click on their head and they will return without turning green.