@turkay1-- Lemon juice and yogurt lightens skin complexion. You can mix them together and apply it as a mask several times a week.
But the best way to maintain a light complexion is to stay out of the sun. In the summer, I never go out between 11am and 3pm because this is when the sun is strongest. And when I do go out, I wear long, light clothes, a large hat and sunglasses to protect my skin. Suncreen is a must too.
I think we should also keep in mind that even though environmental factors affect our complexion, it's mostly genetic. So it's not possible for someone with a brown complexion to become ivory white.
We should concentrate on keeping our skin healthy by protecting it, drinking enough water and eating a balanced diet. If there is hyper-pigmentation or another skin problem, we should see a dermatologist and have it treated. I like pale skin too but I also love myself and I have accepted my skin color the way it is.