Roundels are such common charges that each colour roundel has its own special name, so it is an error if these are given a colour. These are:
Bezant, golpe, guze, hurt, orange, pellet, plate, pomme, torteau
The matching of name to heraldic tincture is left as an exercise for the reader.
The bounding box is a special charge that can be used to debug placement problems. The normal "up" direction is clearly indicated and the shape will expand to fit all of the space available for a charge.
Click on an image to be redirected to the Create Page to find artist credits.