I made the backing and hanging sleeve the same as the little border on the front, red. I am not sure if there is a hard and fast rule. I used a link from the internet on how to make them. My 13 year old sewed on all the tiny hanging sleeves. We made 6 for donation and two for us (son and brother) and one for my brother's wife. If you want I could post a picture later today. Just pm me.
Here is the board link to creative Sheila's post when she requested help to make these.
http://www.quiltingboard.com/t-99987-1.htm