Dressy(ish) pants options other than jeans?

I am going on my schools 8th grade washington DC trip. We are not allowed to wear jeans or just stretchy (exercise-like) pants. No black or any colored jeans. The only pants I have are jeans and sweatpants. I am willing to go buy some pants, but I have NO idea what to buy (I won't wear corduroys). Any ideas?