The general dress code guidelines for men during an interview are that they wear suits in navy blue or dark blue. This is preferred over gray or charcoal gray. Sometimes brown can be acceptable but not on the first interview. Usually, the darker the suit, the more authority it carries.
But beware; a man should never wear black to an interview unless he is applying as an undertaker. A two piece suit is acceptable as is a three button single breasted jacket. What matters most is that the suit fits well and it is good quality. The trousers should fit comfortably at the waist and a slimmer fit is preferred. There should only be a slight break where the trouser hits the shoe. If your ankles are showing, they are way too short.
A man at an interview should always wear a long sleeved shirt either in white, cream or pale blue. Monograms are not a good decision on the first interview. If you tend to perspire often, cotton shirts are the way to go professionally cleaned and starched. The higher the cotton content, the better the shirt will look. Make sure your shirt fits the neck properly and that the sleeve cuff ends just at the wrist. All your interview clothes should be professionally cleaned and pressed and ready to go.
Ties that are cheap looking do not give off a good first impression. A pure silk tie makes the most powerful professional impact, has the best finish and feel, and is easiest to tie well. The tie should complement your suit, not match it. No outlandish, flamboyant ties are necessary. The length of the tie should be extended to your trouser belt.
Shoes should be brown or black leather. No other materials or colors are acceptable. Socks should complement the suit, blue, black, gray, or brown. A briefcase is a symbol of authority, which makes a strong professional statement. Brown or burgundy are the colors of choice.
As with women, men’s jewelry should be kept to a minimum. No visible body piercing or tattoos -if you can help it. This clean cut, well manicured image says a lot about a professional man. He should smell wonderful, have a nicely trimmed hair cut and appear clean and crisp. Good luck.