Can I put 1 referee for employment, and 1 for character check? Or my previous work colleague instead of a friend?

Check the email you received with the reference check information, as recruiters may mention whether they do or do not accept certain types of referees. 

If you're still unsure, reach out to your recruiter to confirm. Referoo can support character references, but it's up to the recruiter whether they will accept that type of reference for the role you are applying for.