Um, I'm not that great at explaining..':D But, if you make a light reflecting off of a character/object(anything), make the color lighter on the front, and in the back, make the original color a little bit darker. Example, maybe like this? -->

ok, to do multi-color shading you need the base color first, for example, orange, you can shade the orange with a darker red, never do it with another type of darker orange, no, because it will look "dry", try to make it with dark red or even dark pink, to make the shading of the red do not use dark red, use purple, for pink, use red or purple, to shade green use blue, and for blue use purple, for yellow use orange, and for white use light pink, light purple, light blue, light yellow and light green, never use pure black for coloring, use a "lighter" shade of black and to make the shading use pure black!

Try looking up references it hwlps