It's generally not the LFS store using hormones but the breeder who supply's the store, fully colored fish demand a much higher price tag so where there is a demand someone will find a fraudulent way to supply. The peacock in your other thread is perfect example of a hormone dosed fish. I would make the store aware of the issue giving them the benefit of the doubt, but if they're aware of the practice I'd be taking my business elsewhere.
Just because they are hormones based fish doesn't mean they will necessarily be sterile either, while there is a chance it's a not given in my experience.