Why does my rose bush have dark red leaves?

The plants are new and I know the red color can just be the color of it's new growth, but the largest leaf is about as long as my thumb and shows no sign of becoming greener. In addition, the leaves are kinda wilted and soft, they sag instead of standing out. We had a period of much rain, which is when the leaves first started to grow, but lately it's been very sunny with a temp of about 85. They're planted in a mixture of soil and clay, since the the ground is mostly clay.