Maybe that's a just a misunderstanding of "metal" because there is just no metal which graciously shines in any RAL color by itself :] It would be coated, carpaint or something similar. Maybe you should just show an example of what you are after.
If you want to have it just more "shiny" then do the usual for a basic metal material: diffuse=0, reflection=1, raise reflection IOR to something like 15-50, put the color into reflection color, play with glossiness. And remember that the look of metal/highly reflective materials very much depend on the environment which they reflect.
Good Luck