I just got an RP a few days ago, I’ve just converted my first batch of cr3s to DNG and the colour was pretty bad opening the DNGs in RT. I did manage to adjust some pictures to look sort of OK, but obviously it wasn’t doing as well as RT would with files from other cameras I’ve tried (all officially supported). It seems like some progress might be being made on cr3 support in RT, but I know next to nothing about how making software works, so I have no idea when they might get official support. In the meantime, I’ve been able to get a little bit better results by using the .dcp profiles frrom Adobe DNG converter. You can probably find them in .wine/drive_c/ProgramData/Adobe/CameraRaw/CameraProfiles/, or just c/ProgramData/Adobe/CameraRaw/CameraProfiles/ on Windows.
There’s an “Adobe Standard” one for the RP specifically in the “Adobe Standard” folder, and I’ve actually had fairly decent results using the profiles for the 6D Mark II that are in the “Camera” folder. There are no camera matching profiles for the RP in Adobe yet apparently, so you won’t find any in the “Camera” folder at this point. For me the Neutral profile for the 6DII is looking the best, better than the Adobe Standard RP profile. Either is a lot better than the DNG as it is by default when you open it.
I would think the files will look even better straight away when opening them if/when there is official support, but for now, this is the best workaround I’ve found if you want to process them in RT.