For anyone like me that came across this and it didn't answer the question.

You need to uncheck the file state return above in the normal e-file section VI - "Electronic Filing of Tax return Information" uncheck next to the  "File state or city returns electronically" BUT only after having selected to e-file an amended state return for Colorado in section VII then going to Colorado return and going to the bottom of the information section to see that indeed the program has checked the amended filing box.  At least that is what allowed for me to move forward with filing an amended CO 104x.  Once I unchecked the box in section VI and exited to the E-file center the line for the state return now said "CO Amended" in the Return Type section.

Hope this helps anyone who was lost for 20 minutes trying to figure this out.