Hi, you seem to have developed contact dermatitis
with your hair dye which later on healed with post inflammatory condition. To treat the same, i hope you discontinued using that particular dye. Secondly use a good sunscreen along with oral antioxidant and vitamin c tablets. Also prime your skin with good depigmenting agents like glycolic acid
cream or triple combination(hydroquinone
, tretinoin, steroid) creams. Peels like glycolic acid or trichloroacetic acid
can be used to lighten the pigmentation. As you have already taken peels with not much effect, is essential to know what was the concentration of peels used. You can also go with mesotherapy sessions with vitamin c and glutathione
along with peels to lighten your pigmentation. Lastly if nothing works, discuss the option of q switched nd yag lasers with your doctor as they yield good results in stubborn pigmentation. Take care.