Why do some MNB-300 / MNB-1000-15 bases have blue I/O connectors and others have green or black I/O connectors?

Issue

Customer has received some MNB-300 bases that have green connectors instead of the usual blue ones.  Are they interchangeable?

Product Line

TAC I/A Series

Environment

I/A Series MNB-1000, MNB-1000-15, MNB-70, MNB-300 and associated base part numbers MNB-BASE-15, MNB-BASE-1000 or MNB-BASE-300

Cause

Manufacturing parts procurement variations.

Resolution

Bases are  fully interchangeable with other bases of the same part number, regardless of the color of the I/O colors.

This color variation does not apply to the power or communications connectors.  
Power is always a three-pin Green connector.  
BACnet-MS/TP is always a three-pin orange connector. 
MNB-1000-15 communications trunk and corresponding connector on the MNB-1000 is  three-pin Black connector.