FC7 Plum Crazy Purple paint question

Primers are generally neutral colors so they won't affect the actual paint. "GENERALLY" However, a red oxide primer can affect the final color of a white car leaving the finished paint pinkish in different lights depending on how many topcoats of the white color that are applied over it. As mentioned by BODYPERSON a sealer over the primer would prevent this. If the car is properly prepped it then becomes all about the paint.