DIAGNOSIS This is not normal. It indicates uneven backlighting or a panel uniformity issue, often described as "backlight bleed" or "color temperature shift." It is a physical panel quality defect.
FIX There is no user-serviceable fix for panel uniformity. First, test the monitor with different devices and cables to rule out a source problem. If the tint is always present in the same location, the panel itself is defective.
IF THAT DIDN'T WORK You can attempt a minor adjustment via the On-Screen Display (OSD). Press the physical button to open the OSD. Navigate to Color Settings. Adjust the 'Color Temperature' setting. A 'Cooler' setting may reduce the appearance of yellowing, but will not fix a localized defect.
HEADS UP This type of issue is common in budget IPS panels. It is often most visible on solid gray or white backgrounds. If the monitor is new and the tint is severe, contact KYY support or your retailer regarding a warranty replacement. Document the issue with a photo.