While the Dell 3100cn printer is officially not supported under Windows 10 it does work with an alternate driver that ships with Windows 10.
To configure it select the HP Color LaserJet 2500 PS Class Driver during the printer installation. The colors print well on both the Windows 10 test page and from other programs.
Interestingly some of the generic Microsoft drivers such as the Microsoft PS Class Driver correctly printed the Windows 10 test page in color but appeared as not having color support to other programs. Also the Dell 3110cn Driver, while very close in model number seems to invert any colors that are printed.