Congratulations!
The yellow one is Frühlingsgold, a German hybrid from the 1930s. It has a citrus fragrance inherited from its parent Disocactus macranthus.
The first two are NOIDs. Depending on the real color of the first we called it either Red or Magenta. We have three slightly different NOID whites. I think this is the one we called "thin stem."
The beautiful red/orange is Tabasco.
I'll need to look at some photos. I think the last is Vera.
A good place to look at photos is the
Epiphyllum Society of America.