As far as I know, there are no subspecies of Bombina orientalis. My understanding that it may be genetics that produces these different morphs within certain populations. Most fire-bellies offered for sale are wild caught. If a toad is collected from a population whose diet is low in carotenes then it's not likely to have brillant red-hues on its underside. Same goes for a captive bred toad that have not been given insects that have fed upon carotene rich foods, such as carrots or sweet potatoes.