Heavily detailed Painting

Hi Kienan! I have a question about rendering a final piece, especially heavily detailed artwork (intricate design what with a lot of colors and materials, also with background). How would you go about coloring it? Do you tackle each part of it individually or is there a way to use time more efficiently?

I'm not looking for an easy way out, I was just wondering if making a layer for each color and material seems a bit too much. (In case you're wondering, I'm in the process of making a fanart of Aloy from the wonderful Horizon Zero Dawn)