I've loaded up the very latest PPro 2019. So far so good but on the General Settings I'm unable to set "enable color management" as it is grayed out.
I've tried with Windows HDR WCG support on and off.
What are the requirements for the new Color Management?
The only requirement for display color management to work is that you are using GPU acceleration. Please check that CUDA is selected in Project Settings > General. If it is grayed out, that means you need a Nvidia driver update. PPro 2019 requires CUDA 9.2 drivers (Version 411.63 or higher) Download Drivers | NVIDIA
the driver update did the trick.
thanks very much