(all black lego minifig army by unknown)

Decals and colour add personality and uniqueness to minifigs, they help bring out the story telling effect of minifigs, however flat colour minifigs seem more artistic, statue like if you will, however, in their faceless nature flat colour minifigs are really cool, they speak volumes for the shape and form of the minfig rather than express personality. As such using flat colour minifigs can be really powerful especially in a photographic and architectural/artistic way.