Tips on how to make Green flame fuel?

OK so i need to make something burn green, unfortunately this fuel(thing im gonna burn) has to have no color and can be applied to surfaces(imagine something like glycerin that you can place on a surface which will burn green). it has to be easily bought and should be non-toxic. if you guys know any chemicals i can try out mixing, it would be a lot of help >:) . if there are no non-toxic solutions, ill take the mildly toxic ones >:) thanks a lot