From memory I believe use the yellow for 12-10awg and the blue from 16-14 awg. If you are crimping directly onto the CIMs then use the blue ones, if you have more leads going between the CIMs lead and the MC then use the appropriate connector for whatever gauge wire/breaker you use (recommended yellow-12awg-40a).
Our team preferes the fork connecters, such as these:
http://australia.rs-online.com/web/p...minals/534626/ because it allows us to remove cables without undoing the screw all the way.
However the best connector would have to be Anderson PowerPoles, provide genderless and tool-less connections and make swapping motors out easy:
http://www.powerwerx.com/anderson-po...owerpole-sets/
Hope that helps