Neutrals 101

There are three primary neutrals; black, blue (of the dark and navy variety) and brown. There are very specific rules as to with what you can wear each. These rules are either not known by many, or ignored. If you perpetrate the latter, you are a fiend. If you fall under the former category, here is a quick rundown of the Rules of Neutrals.

1)Under no circumstances are black and blue to be worn together.
2)Under no circumstances are black and brown to be worn together.
3)Blue and brown may be worn together.

Ex. If you wear a navy sweater, you must wear brown accessories (belt, socks, and shoes).
If you wear a black sweater, you must wear black accessories.

In their own category are the Power Neutrals, namely olive, grey (including charcoal), and khaki. These can be worn with any of the Primary Neutrals, however it's preferable NOT to wear black with khaki. While this is technically not breaking any rules, it is a tad outdated in my opinion.

Also
men: match your belts with your shoes and your socks with your pants.
Blue denim does not count as a Primary Neutral, it is a Power Neutral. An entry on wearing denim with denim should follow.

I have a much more extensive and strict list of rules associated w/ Neutrals, but I'll spare you.