It is possible to print without material by manually changing the filament (setting filament change or pause) in the slicer, depending on your printer and sw support.
These were my settings and colors for my print that you see in the picture. Your results may be depending on the filament you use.
PLA Anycubic Black Transmission Distance: 0.3
PLA BambuLab Basic Blue Gray Transmission Distance: 3
PLA Elegoo + Gray Transmission Distance: 3
PLA Elegoo Basic White Transmission Distance: 7
This print uses 4 unique filaments
Swap Instructions:
Start with Black
At layer #10 (0.88mm) swap to Blue Gray
At layer #13 (1.12mm) swap to Gray
At layer #16 (1.36mm) swap to White for the rest.The author marked this model as their own original creation.