MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
Hmmm, strange, I tried your suggestion. But this is what I initially had. I found on the German RepRap Forum following suggestion that worked for me ...
2B => blue
2A => yellow
1A => PINK
1B => ORANGE
Do not ask me why this is working :) but the thing turns like a dream now ...