There is no spoon.
I found that the hostapp included in https://github.com/thunderbug1/Spherebot-Host-GUI was a bit disappointing.
It required the gcode to be split in one file per layer(color). But the Inkscape plugin had them in the same gcode file, with added "M1 (Layer 3 Red)" between each layer. That seemed to be a good command to use, so this program will prompt You with a dialog to change pen and then continue printing.
Serialsettings are hardcoded in the source. Baudrate 256000 Stopbits 1 Flowcontrol None Databits 8 Parity None
Precompiled for Windows x86 with MSVC2010 https://dl.dropboxusercontent.com/u/748397/SpherebotGui/SpherebotGUI.zip
All-in-one with Arduino code, and Inkscape (in German) change "LANG=de" to "LANG=en" in InkscapePortable/Data/settings/InkscapePortableSettings.ini