Marriage Traditions

Hello mama's! I know this isn't pregnancy related but I am getting married on Christmas eve. My grandmother says for good luck you have to wear something old, something new, something borrowed, and something blue. For something old my grandmother is bringing her mother's jewelry over for me to look through, for something new I am buying a dress for Saturday, for something borrowed well obviously im borrowing something! (Most likely from my mom) but I'm stuck on something blue. Especially if I will alrwady have jewelry on for something old & something borrowed .. what could I do for something blue!?!?! Any ideas would be appreciated 😊