Oncidium alliance plants (this includes your Colmanaras, as well as the Burrageara) have much more short-lived flowers than Phals do, so the deterioration you're witnessing may be perfectly natural. Also, if you bought the plants in bloom, it's possible the flowers were damaged in transit. (Possibly en route from the grower to the retailer.) How long have you had the plants? How soon after getting the plants did you notice the "deterioration" of the flowers?
I don't have much experience with Zygos, but I believe their blooms are even more short-lived than Oncidium alliance plants.
How does the foliage look? From what I've read in your description of growing conditions, it sounds like you're doing the right things for your plants. Therefore the deterioration of the flowers is not indicating unhappy plants. If, however, the foliage is also wilting, you may have something wrong.