It is a good idea to wear socks that are the same, every sock should match the other, it is not so obvious. Furthermore, the color of the socks must be combined with that of the trousers, without creating too much contrast, unless you have your own personal and original style, capable of reflecting an eccentric personality, in which case you are free to dare and break all the patterns. Go ahead not only for colors but also for geometric patterns. Well be it to match the stockings also to the shoes and the tie
According to the Independant Streetwear Designer, the rule, for a gentleman, is to never expose the nakedness of the leg in an involuntary way. A bit old as a custom but good taste never goes out of fashion. Think of an element of distraction that can be a strip of hairy skin that comes out from under the trousers.