you can, but if its a dry flake you dont wanna add it past the saturation point of you base or its going to be like spraying oatmeal.. in which case youll need to add a clear basecoat binder to your color so it dosent end up sandy when you spray. if your adding liquid pearls to your base you shouldnt have a problem, just thin it out accordingly.... colors always pop better if the pearl or flake is dusted over the top of a drab color. the amount of pearl youll need to add to get a nice effect to the base you may as well just spray an ice pearl over the top mixed with a clear binder, heaps easy to do and not that expensive.... or pick a factory color that has a ton of pearl in it to begin with and looks sick. just my 2c