I think you took the 'album' definition literally here .No venustum varieties, so far known to mankind, breed like true albums. If you find one, that does, you will be creating a true botanical sensation, i.e. a venustum with a flower entirely without chlorophylic pigment (no green), all white.
In genetics, the term album lineage includes all white, yellows and greens that do not have coding of anthocyanins in floral parts. My point in this case with venustum measuresianum, these basal anthocyanin do not affect this genetic inheritance of these white/yellow/green progeny in the rest of the flower parts other than the basal warts.
This is true. But there are others like micranthum var. kienii, delenatii album and possibly white forms of hangianum albums and emersonii albums (heresay but not proven).Braem expounds lucidly on the subject of albinism in his monograph on The genus Paphiopedilum. According to his 'notes on albinism, there are only three species in the genus, that can produce true album (i.e. all white) flowers, namely P. bellatulum, P. godefroyae and P. niveum.