Not enough info here to be helpful.* You don't say if this is your first year with this rose.* If not, when did it bloom last year?* Has anything changed in the environment?* Anyone spray herbicides nearby?* Maybe the red leaves are part of the habit of the rose and it's a late bloomer.* Can you post a picture and let us know where this rose grows?
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.