let me throw this out there: taxonomists are idiots. and the rules they abide by are as well. phillip cribb can send his attack dogs to my apartment and guido braem can whack me over the head with a bar of soap. if you are the first to "validly describe" (whatever that means) a form of a species, you can call it whatever you want. if you wanted to call an orange flower "fma. album", you presumably could do so. and even if you are an orchid-smuggling idiot who feigns ignorance of the rules, however stupid they might be, your name will be immortalized if you manage to get the plant described and the name published in a valid manner (validity of having the specimen does not come into consideration).

you see "variety" used all the time, but the proper term for these color forms is also "forma", abbreviated fma. variety is supposed to be applied to distinct populations of plants with some real difference, not to a sporadic mutation that produces a different color.