My lttle foxface is acting weird!

[foxface]

My one spot foxface has been acting a little weird in the last 2-3 days.
She's only a baby, about 1 3/4" long. She adapted very well on the first day we got her (june 25th) but the last 2-3 days she's been acting weird. She goes and sits in the bottom corners of the tank and her color changes to her night time colors (pyjamas). She eats well has no signs of spots or bite marks.... If she sees me coming she changes back to yellow and swims around.
Any clues?
Louise