In order to print with the QuadFusion you'll need a plugin on Cura called MELT. MELT is helpful for individual layer color printing and gradient printing. This guide will assume you have already installed Cura.
Instructions for downloading MELT:
Click “Download Zip”
Once you have downloaded the Zip file, go to your Local Disk → Program Files → Ultimaker Cura 3.3 → Plugins → Post Processing Plugin → Scripts
Once in Scripts, copy the MELT.py file, from when you downloaded MELT, into this folder. You should now be able to use MELT when using Cura
You can check to see if this plugin is now in Cura by opening a new Cura page and looking under Extensions --> Post Processing --> Modify G-Code
Next, look under the drop down tab and see if "Multi-Extruder Layering Tool 3.4.0 (MELT)" is there.