All my woven white shorts (Nadal, Delpo shorts) get dingy after a few months of use. But the blue-tinge might be your detergent or something.
It's like a white over-grip. It'll just get more off white the longer you use it.
Yonex VCORE Tour 89 w/ Volkl Cyclone 18 @ 48
Yonex EZONE Ai 98 w/ Yonex PolyTour HS 125 @ 45