Solidworks logo,

Change the filament for red at 1mm height , for black at 1.2mm and for red again at 1.3mm.
Print with a 0.1 layer height or increase the z-scale to be able to have a layer of black.

Use only one color of red, the color difference is made thanks to the black layer

If your printer has Marlin, you can change the filament by modifying your g-code and adding the line M600 before the concerned layer