Betsy, those white roots are healthy and not dried out. When you water them they will turn green. Orchid roots have a spongy coating on them called (I think) velamen and it absorbs water. Dried out, dead roots are brown or beige.
That plant looks fine, and I wouldn't worry about the lower leaves yellowing. Orchids are slow growers but do shed the old leaves periodically. It will grow new ones over the summer after the flowers are finished.
I would take a knife or a can opener or something and make some more holes in the sides of the clear plastic pot. The one thing above all that Phals like is for their roots to be able to breathe, and dry out after they're watered. Be sure there's no water sitting in the outer pot, too.
