The correct name for the plant is
(Neofinetia falcata x Darwinara Charm) 'Rainbow'
it is not a registered hybrid, so Darwinara Rainbow is incorrect. there's nothing wrong with the label.
well, if it is written on the label that it is Neofinetia Rainbow, as originally posted, there is something wrong on it However, if the label is as Lambelkip indicates, it is perfectly correct... However, even if not yet registered this plant is still a Darwinara
Neofinetia x Vascotylis = Darwinara
Neofinetia x Darwinara = Darwinara*
*(as for my understanding of the nomenclature - please correct me if I am wrong)