Since you purchased the bag on Amazon, the easiest way to exchange the sleeping bag is to place a return order. You need to go into your account and open up your orders. Select the order that includes the Hyke & Byke sleeping bag and then click the button next to the product titled "Return or replace item". You will be required to tell Amazon why you are returning the sleeping bag and you can select exchanging for a different size. You will be fully refunded and provided a shipping label to return your bag in all the original packaging (plastic protective bag and cardboard shipping box). This helps Amazon employees restock our sleeping bags. Lastly, you can place a new order for the correct size and color Hyke & Byke sleeping bag!