This theory is also a subset of the underdress theory and is another way of explaining the difference between the fabrics of the hem of the underdress and the bodice. The theory goes that the bodice and skirt are two different colours. This is perhaps the least common theory of all. Waist seams only appear to come into common use (according to contemporary art) in the 1460s so the method of making a dress with a waist seam was still relatively new. Had they made the leap from waist seam to a separate bodice and skirt from differing fabrics?
That said there are a few pictures that suggest they had, however there is no proof that they wore these under a Burgundian gown. It is, however, a valid interpretation.