I am very unsure about this one. It looks like a peloric form of D. sulphurea (note the large/mutated labellum) however it is unusually pale and has some minor blotching on the petals. That might suggest a hybrid between D. sulphurea and D. nigromontana and maybe even a peloric hybrid. I am interested to hear what others have to say.
Ah of course! That would also explain the pale colour. I didn't even consider chryseopsis because there are no nearby records. It's a strange hybrid given flowering tends not to overlap.