2 color test with a single extruder (pyramidal hourglass)

I wanted to try to print in two different colors with a single print head. The plan was to switch filament at a given point in the print. I designed a sort of pyramidal hourglass (one pyramid at the bottom, another inverted at the top, and some overlap between the two).

I used PLA for this. White on the bottom half and black on the top.

I used Simplify3D as my slicing and printing software, but I'm pretty sure this could be done with Pronterface as well.

I broke the model into 2 halv