If I paint my car with a color that doesn't have metallic in it, then

[e_z_maglwidget@yahooecom]

later spray metallic? Will that make the colors blend together, I have the spray paint that matches my car color but it doesn't have metallic in it though, if i bought the metallic spray paint, is it worth it or just have a pro do it?
(I'm using auto paint spray for though))