Yep as @dimitrie said, The renderMaterial contains all the PBR material properties that you should need to convert the material.
I’ve actually implemented material conversion over on the master branch if you are interested in my implementation.
Here are some helper methods I wrote:
https://github.com/specklesystems/speckle-unreal/blob/master/SpeckleUnrealProject/Plugins/SpeckleUnreal/Source/SpeckleUnreal/Private/MaterialConverter.cpp
https://github.com/specklesystems/speckle-unreal/blob/8b15e39ff7049e94f2b850803e4559814efda7c9/SpeckleUnrealProject/Plugins/SpeckleUnreal/Source/SpeckleUnreal/Private/SpeckleUnrealManager.cpp#L219-L269
FColor has a constructor that takes a int32 ARGB color, so there is no funky conversion that you have to do.
Let me know if you run into any blockers 