Firefish question

Hey guys so i have had quite a few regular firefish but never a purple.



My LFS got a purple in for me today and i just have some questions.



Can i mix a purple with 2 regular firefish?



I heard purples don't get along in pairs. But regular do well in odd amounts from my knowledge like owning 3 instead of 2.



Anyone with a purple give me some information that would be great.



THanks