The curved display of the some Samsung Galaxy S6 can have display errors like defective pixel or a gray shading. Most of the display errors during normal operation are not observed, which is why we recommend you to check this in more detail.
This works as follows with your Samsung Galaxy S6:
1. Open from the home screen the phone app and change within on the tab "keypad".
2. Enter here now the following code: *#0*#
3. This code now opens after the last input the Service menu.
4. You will see various white boxes, there in every field a functional test can be found
5. Now tap on the first series fields "Red", "Green" and "Blue". If a pixel function is incorrectly, then this can be here very quickly recognized, because the pixels will show at one of the color tests only a black color
6. After this test tap on the next field "Touch". Here you can check the touch surface of your Samsung Galaxy S6.
If the tests are positive, then your Samsung Galaxy S6 fortunately does not have any display errors and it's all right. It makes sense to perform this test from time to time, so that you recognize the defective pixels within the warranty period.