Help! How Do I Restore My Medium Chestnut Colored Uggs Back Or Close To Their Original Color?

ok so i have the medium colored uggs boots and they of course are faded and damaged from 2 years of slight water damage but on the front tip of the boots they are veryyyyy dark from water damage…i let them dry and now the fron tips are super dark..is there any way i can clean them, dye them, or clean them without making the damage work…any way to restore their color???