I am not currently highlighted but I used to be relaxed/highlighted and got my hair torched by the egyptians weekly, not a good look-my hair was dyed and fried. I didn't really take care of my hair back then like I should..but I did use conditioners that were targeted towards colored hair. You will want to take all the same good measures that you take with your hair in its current state. You will probably need to up the moisture and maybe the protein in your routine and limit your direct heat use.
I'm sure those with current experience will chime in...