The Vanda Rothschildiana we usually see on the net, and also on books,
looks more of a typical multi parented blue vanda, and less of a first
generation hybrid between V. sanderiana and V. coerulea. I have a
picture of mine that flowered here (look at the archives of the
group), I bought it from Orchids & More (Germany, www.orchideen.com),
and it is typically intermediate between the species.