Has anyone ever gotten a complete surprise from a freshly planted grafted rose?

I succumbed to temptation and got a "body bag" rose from Tractor Supply a couple months ago. I saw what was labeled a "Blue Girl" rose that looked pretty vigorous and decided what the heck. Put down my twelve bucks and carted it home. Popped it in a pot, gave it some untreated soil and manure, plus a little bit of fish goo, and was happy to see it take off. It quickly produced about nine buds on the grafted canes. But when they started opening up.....they weren't light purple. They were a magenta color (I live in Central Florida....used to be 9b but just got "upgraded" to 10a here.)

These blooms are definitely not coming from any suckers. They are all from canes grafted onto the rootstock. If they were from suckers (do they appear that quickly?), I'd just call it a Dr Huey and deal with it.

I know that Blue Girl's parentage includes a rose named "Magenta". Is it possible that my rose reverted to a parent?

If there had been a magenta colored rose in those pallets at TS, I would just think it got mislabeled. But the lady said they just got them in the day before, and the pallets were still pretty full when I bought it. (The other varieties were ones like "Tropicana", "Gold Medal", "First Prize" and "Mr Lincoln" - all old classics.)

Sorry if it's a dumb question, I just don't know what happened here.

And no, not buying another rose there, no matter how tempting. ;).