i don't want to burst your bubble or anything here, but you really don't need a specific "outfit" for parkour. really you just need to were whatever is comfortable and doesn't hinder your moment in anyway. but hey, if you want a certain outfit for parkour, by all means do whatever you want, i usually wear the same thing every time i go out to train( but thats b/c all the rest of my cloths have chains and buckles and stuff all over em and weigh about 15 pounds)..lol
i guess where im going with this is, don't feel obligated to wear a certain thing... be free, wear whatever works