In DragonVale for the iPhone and iPad, the Gold Olympus Dragon is a limited dragon only available during the Olympics.
To get a Gold Olympus Dragon, you need to breed an Air hybrid with a Lightning hybrid. For example, Blazing + Crystal, Blazing + Storm, Fog + Storm, Willow + Quake.
Check out my DragonVale Breeding Guide for more dragon breeding combinations as well as other Air and Lightning hybrid combinations you can use to get your Gold Olympus Dragon.