The dragons are colored much like dinos in the game - they have color regions that on spawn are randomly selected from a list of in-game colors. The color options can be found at the bottom of this page here: http://ark.gamepedia.com/Entity_IDs

There's no option for a gold color in the game's default colors, so a golden dragon wouldn't be possible, but some of the yellows might look kind of gold in certain lights.

Or if you have Annanuki Genisis and their colors you could get it gold. Or admin can have special event to make one gold. Hermit is correct closes is "Dino yellow" on all zones.