Frontosa has suddenly colored up?

[LostInFish]

My Frontosa has been very dark colored since I bought him. Today I added a new fish to the tank and the frontosa's color "stripes" just came in very nice and bright why would this be. Maybe it's more comfortable with more fish ? Before he was very dark and had almost a solid body color.

 

[Fishfur]

Very likely a reaction to the new fish. I wouldn't be concerned about it.