Passmark performance- 2D Graphics Issue

[conan]

Change color depth to 16-bit under W764, then open the "Performance Test" with administrator and click the "Tests" option and select 2D Graphics ->All, The test picture is show abnormal.
But can't reproduce under 32-bit color depth.
Does this tool whether support 16-bit color depth or not?

[David (PassMark)]

The image used in PerformanceTest is a full colour image (32bits). So if you display it at a lower bit depth, then it is normal that is doesn't look right. The software make no attempt to dither the image to simulate a wider gamut.

But the question is also irrelevant nowadays. 16bit colour is dead and has been for many years. It isn't even an option in Win10.