modifyColor() modifies the color of an object in a multiplicative manner, as opposed to modifyAddColor(), which is additive. In a bizarre twist of logic, modifyColor() takes an RGBA as an argument, while setColor() takes an RGB. Apart from the inclusion of the alpha channel, modifyColor() and setColor() work in about the same way. Of course, one modifies the attribute of an existing object, while the other sets that attribute for objects that are yet to be created.