Paph. insigne f. sanderae (the 'flavum' form) doesn't have any pigmentation at the base of the leaves. Here's one of mine to demonstrate...
(sorry for the bad photo quality... just did it somewhat fast)

Paph. insigne f. sanderae


I do see in your cross the presence of both Paph. insigne f. sanderae and Paph. sukhakulii... it's a great flower!

-Pat