POL, don't listen to the old jokers. Read the book: Airline Pilot Interviews: How you can succed in getting hired, by Irv Jasinski.
If you apply for an US/Asian/English spoken country's airline: suit with a white/lightly blue shirt and a "normal" tie, no comics or aircraft on it! charcoal color, black shoes. If you apply for a European airline and/or where it's warmer than 30°, you may drop the west and/or the tie.