I'm trying to print 2 colors on a single-extruder printer by having one model print on top of the other in 2 separate gcode files. I am using Cura to do this but am not sure how to slice the 2nd model so its in the air (above the first). The purpose is to have a couple "pieces" of the model with different colors, so I'd print using one color and then print the 2nd gcode file on top of the previous print. Stopping the print just to swap filament for another set of layers is not my goal, as I need to have two colors on the same layer.
So far I've positioned the 2 'pieces" (models) so that one lies above the other. But even though my model's z-coordinate says 4mm tall in solid view, the slicer still slices it as though it is sitting directly on the build plate at 0mm in preview.
(For reference, the image shows the silhouette of the model's actual positioning, but the produced gcode remains at z = 0)
How can I achieve printing a model on top of another in Cura, or if not, is there another software that can do this?