Melanin is natural defense mechanism against Sun. Darker skins are always healthy compared to fairer ones. You can watch my T.V Shows for more details on
1. How To Brighten Dull Complexion - https://www.youtube.com/watch?v=PxH_gTZw_60
2. Blemishes & Pigmentation - https://www.youtube.com/watch?v=teMTS4H1PSo
Next Steps
Protect your skin with Good SPF Cream like Jasmine Sun Protective Cream. Also you have to use Valeda Herbal Lavender Blemish Cream at Night for Depigmentation. A good Face pack like Valeda Herbal Potato pack mixed with natural potato juice will show excellent results.
Health Tips
Always use Talcum Powder over Sunscreen for complete sun block.