I am making a purple and gold cake for this weekend. Last night I covered the cake board in fondant and made the bow loops using white fondant. I would ultimately like both to be gold. Can I use a combination of fondant coloring and lemon juice to tint the white fondant yellow before painting it with gold luster dust? I guess I should have planned better
You can just paint the gold directly onto the white. It will be fine. The gold is kind of thick, so it should cover nicely. If you put some of the gold dust in the cap of the jar it comes in, then add a drop or two (no more) of vodka, you can make a nice paint. When you are finished, just let he cap sit out for a bit and the vodka will evaporate from the cap. I find that a high alcohol content vodka works mush better than lemon juice or extract.
You can buy a tiny bottle of vodka and just keep it with your cake supplies. The one I get is Sobieski from Poland; it has a red cap. The size of the bottle is 50ml. I think it only cost about $2.
I think it's better to paint after it's dry because other wise, I find that the color bleeds.
I agree with Secret (love the name) regarding the gold dust and vodka. The only thing I want to add is that since you are starting with white fondant it will most likely take at least two coats to get a good color. The first coat has to be completely dry before starting second coat other wise you are removing the first coat and be gentle with brush strokes. One other thing I could recommend is to air brush or hand paint the white to a darkish yellow (or even darker color on the attached cake I painted it all the dark purple and got a great gold color over it) and then do the luster dust. If you have gel food coloring that is, I have never tried it with the wilton paste, I use the americolor with a touch of vodka to hand paint all the time.