You could try using an ester, I have pepared some alkyl borate esters which dissolved in alcohol, add a bright green color to the flame.
Cobalt (II) compounds impart a bright blue color to a flame, you could try synthesising some sort of cobaltic ester, or a cobalt (II) alcoholate complex, cobalt alkoxides perhaps.
Never done the exact experiment myself, but I think it could work, say, prepare cobalt isopropoxide, and dissolve a small quantity in MeOH.