Blue orchids are usually referred to as "Coerulea". To your eye they will usually look purple, however, get out your camera and take a few pictures and you will see the blue. I have one that takes interesting pics, called Lc. Blue Madonna of Poland...although since I made those posts I have found out the real name is Lc. Tahoe Rose. There are blue dendrobiums, cattleya, vanda...as well as many others. They are very pretty.