I am taking photos of graduates receiving diplomas - girls in gold gowns, guys in brown. I am using a Canon T2i with Canon 430EX flash. If I shoot all auto, the gold gowns are somewhat underexposed, the brown overexposed. If I meter before I start shooting, and shoot in manual, won't the flash still over or underexpose depending on the gown color. How do I get accurate exposure each time regardless of the gown color?

