Hello Doctor, I Have Difference In Skin Color For My

Hello Doctor, I have difference in skin color for my face n neck with d rest of my body..While the rest of my body is fair, face and neck are tanned and the difference is clearly visible. I consulted a dermatologist and he asked me to use depiwhite cream in the morning and glyco A cream during the nights for 2 months. While the dark spots seem to have reduced i dont see much difference when it comes to skin color. It still is tanned with d difference clearly shown. What can i do about this?