Are there yellow metals besides gold? Are there metals with color different than yellow and grey/silver or reddish?
There is no element other than gold and copper with similar colors; see http://periodictable.com/Properties/A/Color.html.
There are many metal alloys that are red and golden, such as phosphor bronze, which can have a golden hue.
In addition, some metallic compounds may be shiny yellow. Freshly sliced potassium is silvery, but soon acquires an oxide/nitride coat that may look yellow (perhaps due to interference of light?). Of course, "fool's gold", FeS2, was often confused with the element. See http://en.wikipedia.org/wiki/Pyrite and Image of pyrite crystal.
The color of nanoparticles in solution depends on size, so one can create the whole rainbow of colors using a single elemental composition.
See e.g. http://nanocomposix.com/pages/plasmonics for details.
https://en.m.wikipedia.org/wiki/Colloidal_gold shows gold being red and purple.