The depiction of the battle of Sioux in 1797 on a Mandan robe is made using a buffalo robe. This buffalo robe is a cured buffalo hide with the hair still left on. The paint used on the buffalo hide are made from natural pigments. The hide is tanned and painted afterwards.
He used all the elements of art line shape etc
The color is used for to draw the viewer eye to the drill that is holding the ribbon
He used black background and grill placed in front of the back drop that is colorful
hope it helps
