Not worth it, completed full 2-week course & slight shade darker on all teeth

I completed the full 2-week course of using the nightly whitening trays with no improvement in teeth shade. If anything, my teeth now looks a slight shade more yellow! I notice more translucency now on some of my teeth and overall a slight shade darker on all my teeth. I followed the instructions very closely so I did everything as stated. I also did not deviate from eating all white foods which is a very annoying process. I expected good results considering this is a very expensive treatment compared to others out there, but instead I got the opposite. Poor results, NOT WORTH IT!!