You bought both sides of the fabric, so you can use either side. I have used the "wrong" side of white-on-white or white-on-cream fabrics in projects where I wanted to "tone" down the color contrast (especially on the cream fabrics). Other projects I have used the brighter, printed side. As I said, you own both sides and you can do what you want. Neither is right nor wrong and no one will criticize your choice.