Color markers are limited by the heavy cost to obtain and maintaining the supply of the refills cost a bomb. Essential collection of colors - neutral grey tones of N1, N3, N5, N7, N9. The rest depending of the skin color tone of the subject.
Please see my art piece done during 2016 after the movie Superman vs Batman which I thought Gal Gadot is Awesome!
Lastly, please use marker pad to retain the ink overly absorbed to the paper unnecessarily and do zap a few copies of the outline from a copier to allow several experimental attempts of your rendering at ease and in case of any disastrous mistakes on the art piece.(
