What I planned to do with it always helps me in determining the colors I use. If I'm making something for someone specific, I'd use colors that they have in their home. If I'm making it to donate for a sale I try to use more generic, "could be used most anywhere", type of colors. If it's for myself then I use what I like.
If you're red and white are solids you could use a print that incorporates a little of each color for the background.