discoloration

noun
1
the process of changing colour, or making something change colour, in a way that makes it look less attractive
تغییر رنگ, رنگ‌پریدگی, رنگ‌رفتگی
2
a place where something has changed colour in a way that makes it look less attractive
تغییر رنگ, لک, رنگ‌پریدگی, رنگ ناموزونی
He began to notice a few small brown discolorations on his skin and made an appointment to see the doctor.