Rainbows Acting Weird? Help

[Teddy]

One day I turn on the light in my tank, and realize that one of my dwarf neon rainbows has a yellow stripe running donw his back, and he was being super agressive with one of the other rainbows. I pull him out with a net and put him inot another tank, and the stripe is gone. I figure its the lights reflecting on him in the main tank, so I put him back in, and the stripe is no longer there, and hes not agressive anymore...

Today he had the stripe again for awhile.

Is this one of those Dr. Jekil and Mr. Hide things?

 

[johnnyjtaylor]

Mine get the same stripe, dont know why but its there when the lights first come on then goes. My males always have a bit of a chase and display at each other, nothing to worry about.