Hairstylists.. Hair Crazy Ladies!

So, I am currently a highschool girl in Cosmetology training and I am looking for a new hair color to do. I have a square shaped face (sadly) with a natural medium/dark brown level 4-6 with jet black eyebrows. 
my goal in hair color is to get a black hair color that also shines with a purple tint. any color brands you guys recommend?