I wore a dark blue suit and light/Royal blue and gray tie with a white shirt. The only comment I got was that everyone gets matching suits. It wasn't a good or bad thing just an observation by the captain. On my interview day I saw quite a mix, even a light gray suit. I don't think it matters like it seems to at DL. I think company colors are always a safe bet but the people in my indoc wore lots of different combinations. I even have a friend that got hired in a dark blue suit and red tie. Good luck.