I bought 3 Blue acara's at petsmart before and well I now have a green terror and 1 acara. Same thing happened to me. The terror killed the other acara though. Green terrors make great fish though, I love mine.
Same thing here. Bought 4 of them labeled "Blue Acara" at PetsMart 6 wks ago and found out later I had 3 male Terrors and a female. Kept a male and female. My male is super colored now though, he's gorgeous.