The miniatures market is as much about artistic expression as it is about usefulness for the individual miniature. It is possible that your character or vision of for the miniature has a hammer instead of a sword or wears green under the armor instead of blue. The limit of your imagination and skill are all that keep you from enjoying all the miniatures hobby can offer.
There are some brands of pre-painted miniatures such as Reaper Miniatures Legendary Encounters, although that brand is no longer produced, that take advantage of simple color combinations that are easy to duplicate for beginner level painters
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