Looks like you acted just in time to save this one! I would move this out of the light until it recovers. The earlier pictures to me look like too much sun. In the morning, when the sun is shining on the leaves, you should feel them and if they are at all warm, it is too much.

As for phal leaves turning purple, I have quite a few that have some purple on their undersides and leaf margins. They sit side by side with bright green ones! I find it is usually the plants that have purple or pink colouring in the flowers. With Phals, I have some very bright green leaves and dark green leaves also and I think it is just their different genetics as mine are healthy, and many in bloom and all living on the same shelf in identical conditions. Almost all of mine are NOID's If the entire leaf is turning red or brown tho, it is likely sunburn.

Good luck with that one and I hope it recovers nicely. Some grow keikis readily and others do when under stress.

I mist the leaves of any sick phals I have and if you are careful not to get it in the crown, I find it to be a big help in getting moisture to the plant until it has more roots.

Over a year ago I had the problem described in the #1 on one of my NoId phals - those bumps on the leaves.
After some research I decided that it was edema or oedema.
Here is some information:
PP244/PP164: Physiological Disorders of Orchids: Oedema
It did not spread on to other orchids and did not affect my phal's growth - it successfully grew new set of leaves and fat aerial root since then.

Thank you for sharing this information!