RP from BHB: will it look bad with my dress ivory and my FG dress white?

My FG is my little cousin, and she was a FG for one of my other cousins in November of 2004. Amazingly, her dress still fits her and they want to use it for my wedding and put a pink sash on it. It's white though. Is that a problem? They don't want to buy another dress and that is fine with me. Will it look bad in pics though?

My FG lives in MA and my dress is in NY, so she can't come with me for a fitting. I would hate to have her parents buy a new dress and I know they don't want to. But I hope it doens't look really bad. My dress is in my profile. What do you think?