I wash everything to get the dye out. Have you seen how much dye comes out of stuff!
True story: I bought some new boxers at wally world, well next morning I'm late for class so I rip the pack open and throw on a pair. Well I do my daily routine, school, go for a jog (Trying to lose th freshman 15!) well I went into the bathroom to shower and when I pulled the boxers off the entire area covered by the boxers was the color of the boxers, green! Inlcuding my John Thomas!! I freaked and had to srub for an hour to return my crotch to normal color!
So yes, I wash everything.