alba vs. albina
 

Can someone please tell me what the difference between an alba and an albina flower is? I've been looking into buying a couple more Cattleya guttatas (one of my favorite species), and have found one listed as an alba and another as having albina flowers. When I googled pictures of each, I just couldn't tell the difference between the two. Anyone care to clarify what the (perhaps minor) differences would be between a plant that produced one variety and one that produced another, please? Thank you!

Steve