color changing triggers

So I got a female blue throat trigger from vivid a few weeks ago and realized that the male has better coloring and thought it would be nice to have a pair. So on friday my girlfriend went back and bought me the male and when I put it in the tank they instantly were inseparable. Last night when she was watching them she kept saying something about them changing patterns and colors but I kinda laughed it off because I was busy. To my amazement they were. When they would start looking at each other it was almost like they were blushing or something. Their color would get darker but the weirdest thing was that they would get a sort of leopard pattern all over their their body. Unfortunately now that they are used to each other its not happening anymore but man was it cool.

Anyone ever see or hear of this?

 

lots of fish will do this... can mean a lot of different things but usually stress or fear.