Hi. Greetings. Lightening of the join areas could be done with concomitant use of sunscreens (for exposed areas) and skin lightening agents. Mild Chemical peels would also help. As home remedy - application of yogurt with "kadele hittu or basan" would help but may make skin very dry - so you could try it at your own risk. Please send pictures on private chat or meet a dermatologist near you. Hope this helps. Warm regards.