Men’s XL Tommy Hilfiger polo top. Ombré blue

Gently worn. Only shows signs of wear under the armpit. I have washed it just recently 10/15. I’m guessing the prior use of aluminum gel antiperspirants did this. Only noticeable if you look directly at the armpits. Otherwise is a cool blue ombré effect shirt. 100% cotton. You could probably even dye it?!