Well, they have a variety of golds. They used to have a bright gold called Burnished gold. Not one of my favorites, because its.....too bright for me. They now have shining gold, dwarf bronze and tin bitz.
To get a true bright gold using the Shining gold, believe it or not base paint the area in mithril silver. The bright undercoating will really bring out the gold color. And for that extra shine you could mix in a glaze medium.