I agree with what MsGF has posted. I made little pearl balls from fondant months in advance, and stored in a air tight container. I don’t have an air brush, but would place the little discs/circles in a plastic container filled with gold lustre dust, apply the lid, then shake well. Your circles with be “dyed” gold. This would be labour intensive and time consuming. I have a store here that sells many colours of these little discs. I’d probably buy yellow and paint them gold. I don’t know where your located, your profile doesn’t say. I’m sure these discs/circles can be purchased online.
Creativity is God's gift to us. Using our creativity is our gift back to God. Clarky's Cakes 😎