OK here it is:
Some of you were very close, but the two parents were:
Paph kalinae (also known as Paph. victoria-reginae var. kalinae or Paph. chamberlainianum var. sumatra) and Paph. sanderianum. The darker colors come from Paph. kalinae; that is why some of you were confused and thought that Paph. adductum was one of the parents.
To me Paph. kalinae is very distinct and should be considered as a separate species (compared to Paph chamberlainiaum); as you can see the hybrid made with this species looks different than when you compare it to Paph. chamberlainianum x Paph. sanderianum. Guido Braem thinks it is a distinct species too. The orchid registrar has accepted this entity to be different from Paph. victoria-reginae (they consider Paph. chamberlainianum as Paph. victoria-reginae) for registration purposes, but they still have to decide if it will be accepted as a different species or as a different sub-species. For know it has the hybrid name of Paph. Eine Kleine Nachtmusik
Robert