I would think that it really catches the eyes of your fish. Maybe just intinct to be cautious, and more aware for some reason.....or maybe like how a bull has a negative reation to the color.
I noticed this with my fish too....weird...when i wear a red shirt my aro would go crazy and normally it was pretty chill when i approached the tank....Also i use those orange buckets from home depot and they dont like that either, they get all jumpy starting hitting the hood trying to get out then sometimes the aro would go all crazy then just sit at the bottom of the tank for like half an hour then start swimming normally again....