Question
What kinds of things could change a roses' color? My medallion rose was peach when I bought it but the new leaves are curling, the buds are smaller, and these flowers are all butter yellow!!!

Answer
Medallion is a peach colour do if your new flowers are smaller and yellow then something is wrong with your rose. There is a pale yellow in Medallion so if the weather become very hot, roses sometimes do change colour but will return to their normal colour when the weather cools off. Curling leaves can be caused by a rainy spell and then mildew gets on them. Because mildew burns it shrinks the leaves and so they curl. A virus can also cause the leaves to curl up.  It is hard to diagnose without actually seeing the rose leaves. If the floors are healthy then the rose culled be reverting to one of the roses in it's background. This is called a sport and so there may be nothing the matter in regards to disease with the rose.