For multi-colour 3D printing, a regular dual extruder 3D printer, one that incorporates a single mount for the twin nozzles, is ok. But don’t hope it to be as speedy as an individual extruder 3D printer, looking at the extra excess weight over the print head impacts the print pace. https://shanewmkcu.amoblog.com/multicolored-3d-printer-secrets-51674680