This was a project requested by my son. It is a simple model of Nyan Cat that can be printed as-is, or in multiple colors using the M600 filament swap GCODE command.
The model was scaled to fit a 300x300 print bed, but can be printed at almost any size as long as you only adjust the X and Y axis (or adjust color swap layers accordingly).
For best results you'll want to print with all top layers and no infill. At 0.2 layer height there are 20 layers, so set your top layers to that number or higher.
There are six colors in total. Start with gray loaded, then swap to beige (color of pop-tart), then pink (frosting and cheeks), then red (sprinkes), then black, then white.
Insert filament swap GCODE (M600) at the following layers: 6, 9, 12, 13, 15, and 18.