they look the same, they act the same - I'd say it's the same, but that's just me, not a test result.
I really don't know what breeding them to each other should give for an answer. There will hatch normals (if both are "just" het toffee and het buf) and brownish things which look most likely the same. Does this give any answer? :shrugs:
If there are two females (toffee and buf), I'd breed them both to one and the same male without hets in order to compare those two in more or less one bloodline. If both babys/subadults look the same, I'd assume it's the same. In my mind, breeding two genes which act dominant and look the same to each other would not help very much to find an answer on the question. :shrugs: