Dear Rehman,
The dark spots could be melasma or melanin banding - unrelated to iron. However, if they are a result of iron concentrated in certain parts of the skin IP6 is very helpful in removing iron from the skin - if it is the case taking IP6 faithfully will bring about a difference very quickly. Other antioxidants such as resveratrol, green tea extract will also help. Remember, ferritin is an indirect measure of plasma iron - it may not tell you what your actual iron levels are - especially levels in the organs (the skin being an organ).
Are you currently using desferal or an oral chelator? I find that oral chelators quickly remove iron from the skin. My son's complexion changed 10 fold once he began taking exjade.
If the spots are melasma, topical vitamin C will help - or changing your diet such for optimal adrenal functioning will be helpful.
I hope this helps,
Sharmin