what could these little dots be on my phals?

[NYCorchidman]

I got two mini phalaenopsis this week.
They look healthy and are loaded with flowers.

After close examination of the leaves though, I found some small brown spots on some of the leaves. They are found mostly on the underside of the leaves although smoe are on the top side as well.
The area where the spots form are indented.

I also see some subtle yellow spots, which one of the pictures below show.

Is this onset of leaf rot? What could this be?
If anyone has similar experience with phalaenopsis, please let me know what happened to your plants.

Please no answers based on random possible guessing!