You are correct. According to Christenson's Monograph, flavida is with the yellow background as opposed to white background. I think there may be some confusion here with "flava" vs. "flavida". They are two different forms. The flava form is the yellow with paler yellowish instead of darker brown markings.
Susan
Thanks Susan. Look's like I need to get a copy of it.
I love to get one flava form but yet to find a nice piece, or one breeder willing to sell their precious plant. Much of the breeders in South East Asia still believes strongly in hybridization, and only a couple of novelty phals here are cloned.