The red refers to the the color of the fruit. The blood or zebra banana has reddish fruit. The Dwarf Cavendish will have yellow fruit like normal store-bought banana.

Since bananas rarely fruit for most people who plant them in temperate zones, you may never know which is which as they are very similar otherwise, right down to the reddish bar markings on the leaves which give the red banana its alternate name, zebra banana.

So, flip a coin. If it's tails, the one on the right is the red banana.

Of course, the dwarfism v. the other of one may eventually proove your coin toss to be wrong.

:)

The Red one should have noticeable red color in the trunk, in almost all cases.

The dwarf cavendish should have some red spots/blotches on the leaves at a young age, I'm not sure about the red.

My Super Dwarf, I just noticed, does have a reddish cane or stalk. I can post a picture if you like.

Until they fruit, I don't think you can tell them apart.