What should I wear to a big super cross race, that my boyfriend and I are going to?

My boyfriend and I are going to a super cross race with some family friends. He lives far away, so I don't see him alot, so when I see him, I would like to look nice. Since it is a super cross (dirt bike race) I don't want to get too fancy, but I would like to look nice because I don't see my boyfriend a lot. We have been dating for a few months, so I am comfortable around him.. but i don't want to wear gross sweatpants or a baggy t-shirt. What should I wear? ooh, and btw, it has to go well with pink and grey nike shocks, because I am wearing sneakers. So help me out please! And the race is in August so keep in mind the weather! Thank you(: