I can't notice anything with an all black screen, in fact it looks perfect....only with white or bright monotone colors.
TN's are usually sensitive to viewing angle top and bottom. Check if you still see this when you adjust your angle a bit.
Otherwise, you have a brightness uniformity issue. Unlike backlight bleed, this manifests itself in parts of the screen appearing brighter then other parts regardless of angle and its visible in the colors.
Brightness uniformity issues can happen to all lcd screens (pro screens sometimes have counteractive measures like Colorcomp for NEC's and DUE for Eizo).