Sorry, I cannot give a complete answer, but I thought Gianluca Migliarotti in his magnificent sage green overcoat, double breasted blue odd jacket, purple trousers and brown suede shoes shows us a fine example of how to use colours.
The combination is unusual and bold, yet subdued. The latter effect looks due to use of matt solid colours and fuzzy texture finish.
Source: The Journal of Style in Florence
That is indeed a great overcoat.