I bought a hot pink fish today but dont no what it is?

what is this fish? i bought it at walmart and it is electric red/pink like a hot pink and its not a cichilid or w/e it swims really fast it almost looks like a really long tetra its about a little less then a inch long . on the reciept it sais molly but i also bought a sailfin molly and a male guppy to .