Agreed.. many times there are great examples of two mutations that will look so simular that its impossible to tell. In those cases it isn't that the "Line" as much as our inability to tell it from any other and so it simply becomes a Pastel, Clown, or a Hypo..
Let me clear one thing up...LINES Matter in axanthics cause some aren't compatible with each other. So don't think any axanthic when bred to any axanthic will produce axanthics..