Oh, I am terribly sorry that I did not see this earlier everyone. This is certainly strange and something I have not seen before.
Is it just on a single flower? It is not mechanical, not a fungus, not bacterial, not insect damage. It is not something like either sunburn or a chemical burn.
So what does this leave? Algae? Not likely but it reminds me of water spots. But if they are, why turn green?
Botrytis is a possibility. That arises from humid situations with little or poor air movement. Botrytis is really noticeable on white flowers, often Cattleyas or Phalaenopsis. Tiny black spots that mar the flower and don't rub off is classic Botrytis.
But honestly the green leaves me clueless.
Does the grower have a fan gently blowing on the orchids? Stagnate, stale air is not good for orchids. A nice airy, buoyant atmosphere is ideal!
