She's definitely turning pale again. Not sure what color she's going to turn this time.

That's also her bad eye. From watching the way she swims I'm of the impression that her left eye doesn't work too well; she doesn't see things very well on that side, and she swims tilted to the right so she can use her right eye. It's good that her tankmate is so docile, or her fins would be in ribbons by now.