Welcome JC
Oncidium Jairak Rainbow is actually a Tolumnia hybrid

http://www.rv-orchidworks.com/orchid...k-rainbow.html

Tolumnias like to have their roots dried out quickly. So it will need a well drained medium or mounted. They need bright light, warm and high humidity. In nature most species are twig epiphytes. Their roots get wet from nightime dew or rain and then dry.

Try googling Tolumnia culture, or equitant Oncidium culture for further info