mixing colors is an art, not a science. there really are no rules for this, but i'll tell you how i do it and maybe it will give you some ideas. first, i think of colors as falling into two basic categories: 1) earth tones: brown, green, orange, and yellow (i hate yellow) 2) shades of blue and red, includes purple (if you like yellow, you can add it to this category too.) generally speaking, i don't mix colors from group one with colors from group two. an example red shirt with blue pants or green shirt with brown pants however, there are a million exceptions to this, so don't think of it as a rule so much as a guideline. if you see a green/blue striped shirt you like, wear it. these colors can go well together (yellow + blue = green). i've seen men wear brown shoes and belts with blue suits and blue shirts and it works. it casualizes the outfit a little. note: if you are wearing a lot of earth tones stick with black shoes and belt, as it can be cheesy looking to overdo the earth tones. mr. aybojs pointed this out a while ago, and i completely agree. i should mention that almost all of my clothes are either black, grey, white, or brown. i could pick out an outfit with my eyes closed and it would probably match. i do however like to use colors as spices, especially blue, burgundy, and lavender. i say just lay the outfit on your bed, look at it, and if you like it, go for it. good luck.