Why Is My Teeth Still Brownish-Yellow???

I am 14 years old and my teeth are brownish yellow!. I brush after every meal and before I go to bed. I floss 2xs a day. I eat fruits and veggies because I am a vegetarian. And I go to regular dentist appointments. But my teeth are still brownish-yellow. Can it be my genes because my mom and dad both have beautiful white teeth or the tooth-paste I am using(I use crest whitening plus scope and that colgate night toothpaste plus baking soda). My dentist said I have no diseases and my teeth are healthy except for the color. Please help me out.