Try to copy+rename the 810 generic profile to the 850. To be found here: C:\Program Files\Phase One\Capture One 10\Color Profiles\DSLR (or whatever your installation folder is)
Or, if you create your own profiles, you can put them into the general ICC-folder C:\Windows\System32\Spool\Drivers\Color\
or the specific one of C1: C:\Users\#username#\AppData\Local\CaptureOne\Color Profiles\
The name will be NikonD850-#profilename#.icm or .icc
I never did this, but I don't see why it shouldn't work (as long as you don't have the C1-Sony version of course, which allows only Sony cameras).