You could try Kim-Boo, which is a 24k overlay on silver. The
process is explained in Metals Technic, edited by Tim McCreight ISBN
24k foil is burnished onto piece which is heated to 500-700*F. I
think that would give you the painted on effect you want.
If you are set on using wire, try more of an indirect heat rather
than playing your torch directly on the work. You are leaving your
torch to long in one place, melting the gold wire.