How to remove the yellow stain on my white shoes?

i had these newly-bought white skechers slip on and after i used for about 2 months, i decided to clean it by using brush and detergent. when it dried, the upper part of the shoes turned yellow. i clean it again hoping the stain will be removed but the stain became darker.

How to remove the yellow stain on my white shoes?
i think the detergent you use have that bad effect on the shoes,try to clean your shoes with vanish.



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