If you look at the work that has been done in history, the ones that stand out and stay in your mind the most are the ones that are under-stated. That's like in photography - people think that shooting black and white is easier then color, but actually the opposite in the sense: with a monochrome scheme there is so much to do in shadows/lighting - working with what is the least complicated palette is much harder then working with the full color table. With color - and as an example, the typical hot air balloon photo - the first thing that you see is the color and not the elements, well the color (wow effect) wears off very quickly but the elements are the part that make the art. In working (any art form) - doing it with a minimum of colors leaves the design more exposed for lack of a better word, and that is what will catch a users eyes - so if it's done right it will last - done wrong and it won't even catch a passing glance.