Color theory is a tricky aspect of clothing, and I think I am just getting close to understanding it fully. Regarding colors and when to wear them(not necessarily matching) here is guide to Reddit:
http://www.reddit.com/r/malefashiona...easonal_color/
knowing what colors work best with each other can be very tricky if you want to be more bold, but is rather easy imo to play conservative. Usually dressing in 3 different colors(assuming not all bright and outlandish colors or very very similar colors), is fine. Black/white/grey is fine, but can obv done differntly.
The problem mainly arises when you get too mathcy, in the sense multiple garments have a similar color pattern. like wearing shoes that are red and yellow, and having a red and yellow shirt, or red pants and yellow shirt, or something bizarre like that. This can work if street wear is your style, but for the average person going to a bar, this would look silly.
If you really went to venture into the intracacies of color theory, here is a decent guide:
http://www.reddit.com/r/femalefashio...o_apply_it_to/(although done in a female forum so examples are female clothes). And some things dont really apply to all types of mens fashion(analog color scheme being the most obvious, see my previous example)
Womens clothes tend to be a lot brighter and easier to pull of more bold looks, but similar color theory applies, its just your often not working with super bright colors but more subdued colors in mens fashion.