I'm sure the music reply was right on. Sometimes I leave the tv on to see if this affects their color. The tv only bothers them at night when they see the light glowing 30 feet away.
Although that seems to be changing, they now get up as soon as lights out. I'm glad u have a hide for him. Mine hide all day. Only be seen when it's time to eat.
So it's good u have the same experiance as me with them changing as soon as we get home. It seems no matter how quiet I am, they subconciously know I'm there, and turn browner. Maybe someday that will change, I hope. Although my place is a loft, they're out of the main area, but that doesn't seem to matter at this point. And where I got idea about the eye thing was a sleeping possition in psyche class called the cyclopse, where people sleep with one eye open. Now that's scarey!!!!