First Github Issue is now resolved )

https://github.com/microsoft/vcpkg/issues/4175

OpenColorIO is now a vcpkg port, and can be compiled as standalone library and into OpenImageIO. Meaning now you can compile OIIO library in ~20-40min (nothing compared to, let’s say, 3 days of digging in vcpkg ports/cmake) without any headaches and use OIIO color space conversion functions out of the box without any problems.
Hurray!

Kudos to whoever spent time fixing that.