Both your Robert's Delight and Pat Delight are beautiful and most of the vandas that come out of Thailand are meristems and so are these. Just as the Taiwanese have almost bred the phalaenopsis to perfection, the Thais have done the same with strap leaf vandas and ascocendas.
In Malaysia we don't refer to vandaceous hybrids as simply vandas. We make a distinction between strap-leaf vandas and ascocendas that like more shade; semi-terete and quarter-terete vandas and ascocendas (those that have the terete-leaf Papilionanthe in their ancestry) and are more tolerant of sunny conditions to full sun; aranda(vanda x arachnis); mokara (ascocenda x arachnis) that like full sun; and other hybrids with renanthera, aerides, rhyncostylis, vandopsis and other related generas.
Thus in my posts I'll always say vandaceous unless they are true vandas.
The semi-terete and quarter-terete vandas are very free flowering and are not seasonal; so are the arandas, mokaras. That is why they are the mainstay of our orchid cut-flower industry.The strap leaf type vanda and ascocenda are not as free flowering, but i wouldn't say that they are seasonal either, 3 -4 times a year is about average.
As to whether certain colour types seem to bloom at particlar times of the year - I am afraid I haven't really noticed. Here the blues seem to be more free flowering than the pinks - except for the species coerulea, that flower at most twice a year.