https://www.support.xerox.com/en-us/product/phaser-6510/downloads?platform=linux&language=en
the color drivers are above and come in rpm or deb packages: neither of which are supported on solus.
maybe just maybe someone can help you extract and install from the packages--lotsa good peeps here.
or you might have request at dev tracker above.
I'm just shocked Xerox was around. I thought Lenovo bought everything until I searched your printer.
recap: maybe someone can help you extract what you need from deb or rpm downloads. It's above my head. Or solus could help you at dev tracker (repackage the deb or rpm). I'm confused what (dialogue box or command) is telling you to find the 6310 driver instead (likely a good idea if you can do it)? A search for 'xerox' in the software center shows nothing.
That's all I got for you personally. I've never seen a printer/scanner install that was impossible, but quite often hard as hell.
