Stop in for a cup of coffee

I may need help on this photoshop. Been trying to self teach myself but I'm having issues color matching metallics. It just comes out as a dull base color such as red or orange but can't tell it's metallic. I'm trying to do a Gold metallic color on a 64 polara 4 door and it just looks flat tan.
You need to do a layer in grey scale with monochromatic noise added, then put the transparent color layer over it...It's kinda like doing silver metallic paint on a real car with a candy color clear painted over it.