to ATP, showme!
There's several possibilities to this situation.
1. One color could be a sport of the original plant. Sometimes plants just send off branches that are different, and if they are interesting enough, some people cut those off and root them as another plant.
2. It could be that there was another plant still in the ground where you planted the newer one. Now they are both growing.
3. It could be the grower grafted 2 different plants on the rose. I saw some at Lowes this year that had 2, but they were 2 really different ones, like a white rose and a purple one. They were a good deal! Two roses for the price of one! I bought several, and funny thing, none of them have grown the roses that were pictured on the label. But they sure had 2 different ones on each.
4. Another cause could be, the rootstock to your grafted plant is now sending up canes. That would be the red rose. If that is the case, and it most likely is, you should tear off the cane that is red--tear it off as low as you can--so that it doesn't send up any more. The reason most people don't leave them on is the red one is stronger than the grafted plant, and will outgrow it, and pretty soon all you'll have is a rosebush that blooms once in the spring, but grows to huge proportions. After enlarging your picture and really looking at the red rose, I don't think it's Dr. Huey, the most likely rootstock rose. The placement of the canes isn't leading me to think it's coming from the root either.
5. Maybe the red fades to pink? Has this rose always grown this way, or is it a new rose? I'm really curious to see what it looks like later in the year.