Is it permissible to lighten the skin tone in some parts of the body, especially the 'awrah (private parts), to match the color of the rest of the body, knowing that this difference in color did not exist before?

Changing skin color from dark to white with creams and the like is permissible if the change is temporary. However, if it is permanent, it is not allowed because it is an alteration of Allah's creation and resembles the forbidden tattooing. An exception to this is removing a temporary blemish. Also, a man should not overindulge in such matters, as he should be preoccupied with loftier pursuits.