Tropicals & Tender Perennials: 3 new begonias - need ID please..., 1 by RainGazer

RainGazer wrote:
These are my first begonias, other than the ones I have always bought along with the impatiens and petunias to plant outside. Wow! Who knew they could be this beautiful?
The first two came from HD, and looked a bit sad. I could use some tips on what to do for them, as well.
Here's #1. It has a pinkish-purple iridescent sheen to the leaves. One leaf has turned yellow, and one has turned bright red. They are all red underneath.