Fish actually release chemicals (pheromones, I believe?) that they can recognize, kind of like smell. They recognize each other and stick together, even in the case of the blind cave tetra.
You need to have enough numbers to encourage schooling, which often is at least ten individuals, sometimes more. At the LFS
when they are catching neons, for example, when the tank is full of them it is easy to catch some because they stick together in a school for protection. After they have sold the majority of them they are harder to catch because they no longer school and each fish swims separately to get away from the net.
I have heard of other fish with similar markings schooling together, like clown loaches and tiger barbs.
I don't know about the albino versus regular coloration impacting schooling, but my guess is that the genetic makeup dictates schooling and the colored tetra would "smell" the albino and welcome it into the fold.
I do know that when it comes to cichlids, color is very important and confusion can and will arise when mixing them, in that a female cichlid that has the same color as a male of a different type of cichlid can run into trouble when the two are mixed.
Hopefully someone more knowledgeable will come along and clear this up, but that is the little that I know about it