Saw some neon lampeye fish that were really strange. I never saw them before but anyway I asked the guy at my LFS if they were killifish but he insisted that they were tetras. So are they tetras or are they killifish?
Without seeing them it is not possible to say. The common name hides a multitude of possibilities. The true "Blue Eyes" are related to rainbows, but are frequently called killies, which they are not. There are also tetras which could have that name.
Does the fish have an adipose fin - most likely a tetra, does it have 2 dorsal fins, most likely a rainbow.
Any chance of a picture? while I unfortunately can't help you too much even with a picture I'd be interested in seeing what they look like if you find a pic online before I do.