Volker wrote:
As far as I know, that's a problem of windows itself. If anyone knows how to workaround this problem, feedback is appreciated.
The obvious workaround is not to set your monitor to 16-bit colour. 16-bit colour has very limited support in modern drivers, and 8-bit paletted colour has been unsupported for ages.
Note that once upon-a-time, you could gain a small speed boost by working in 16-bit colour, but these days even if you do manage to get hardware acceleration in a 16-bit colour mode, you won't gain anything over 32-bit. The graphics card is still going to operate in 32-bit, and just round the final result before sending to the monitor.