Last year I started a little spreadsheet called Critical Mass to help culture editors connect with a wider range of critics. It’s now got over 140 critics listed and personally I use it all the time to recommend people for different gigs. It’s also spawned a couple of other lists:
The First Nations and People of Colour in Publishing network has also created a database of freelancers in publishing. It includes editors, designers, sensitivity readers, translators and proofreaders (but not writers).
There are so many resources available if you’re looking to work with underrepresented writers, so there’s really no excuse!