I told my crush something and I'm not sure he knows I was kidding

If he laughed he knows if not joke a little more with to show know hard feelings without saying anything about it. Like him dying his hair blonde if he doesn't know you like him he will then that's actually a nice set up to let him know without being 2 str8 foward.

Well, next time you talk to him you can make a comment like, man, blonde guys are not hot at all, or something along those lines that will contradict the statement you made. Maybe he will say, 'didn't you say blondes were hot?' to which you could reply..."geez, you never get my jokes...." Maybe something to that effect will set things straight without revealing your crush, if you haven't told him that you had a crush on him...

I agree with ladylush but before that tell it to him in a way where he could not feel that you are thinking about it..pretend you don't remember like telling him:"you seem sad and annoyed is it something I did or said" than tell him"oh it must be what I said about blondes before" and then tell him that it was joke and that you really don't like them.I think this would be better.

Just tell him you were joking... be like "hey that comment I made I don't know if you were offended or not and if you were I'm sorry but I was completely joking and I did not mean it" he should be cool with that and if he did take it seriously then that will set it straight.