New monitor problem

Guffmaw

Honorable
Aug 2, 2013
62
0
10,640
I bought a new monitor the other day BenQ GL2460HM and on black background's it's colour goes all like paint has been splatterd in some place and painted green hard to explain and on steam the black background has lines all across it grey black darker grey green blue etc? what is this problem and how do i fix it