I thought they are gold anodised, not painted. Or am I wrong?
Your best bet is to get the nearest gold colour you're able in a spray can. Spray some in the lid and apply with a cocktail stick
Last year I spoke to RS Motorcycle Paint about a touch up for the GS gold wheels as one wasn't listed on their website.
I informed them that the wheels were anodised but they said they could probably produce a reasonable colour match but I needed to get either the bike or a wheel to them. They are based in Welham Green in Herts and to date I haven't had chance to get round to it. If anyone lives close and is willing to pop in for them to colour match the wheels I am sure I and many others on here would be extremely grateful.