It is normal for Windbeam to open a very pale pink and then fade to white. If the layered branch started blooming earlier, it would become white sooner. If they started blooming at the same time and are different colors, then the layered branch is a sport. That does happen and sometimes will revert back in a season or two.

It is a sport since it blooms at the same time. This has been going on for 2-3 years.