I stressed a lot about suit color, but in the end I wore a charcoal suit I'd purchased 10 years prior (only worn once or twice) rather than springing for the latest and greatest navy suit. I say this with no authority whatsoever, but in retrospect I think I stressed needlessly in regard to my suit's color. You're not trying out for America's Next Top Model, and Delta (hopefully) will choose what I wear for the next 22 years. I personally believe that as long as you are well groomed and present a professional image with your attire, the clothing will not factor into your hiring decision.