Here is an interesting item that many people will never have seen before. As you can see this model sheet of King Boreas from "A Trip to Morainia" has been hand colored, presumably by Erv Kaplan. Erv was the director of color and would create the color schemes to most, if not all, of the characters that appeared in the He-Man and She-Ra series. He would use pencils to determine what colors worked best for each character. Once approved, he would then notify the painters what cel paints to use in order to color the characters.
(click on the image to see it at full-size)