My Galaxy SM-T290 after one week of use the background color throughout the tablet changed to lime green. From what ive discovered there could be a lot of reasons an app with permissions may have changed system settings. I cannot find the solution. I will update this in the near future.
l solved the issue it is important feedback for Samsung. There is a blue light filter that is not accessible in settings. It is from swiping down from top of screen turn off blue light filter. It makes the background grey.
