Easy something blue ideas

I'm on a time-crunch and could use some help! My wedding is this Saturday, and I need to find my "something blue". I thought I had it covered. I was going to pin one of my late father's military medals to the underside of my dress. I was sure it was blue....it's not, it's green. I still plan to wear it because I want part of him with me. I just have nothing as a backup. I don't have much of a budget to get anything either. I don't I don't have to have something blue, but it's something I want. Any ideas for a easy and affordable something blue I can get before Saturday?