Blue vs Yellow crimp connectors

[iambujo]

I have a question, maybe one I will regret asking.

The yellow crimp connectors have #10-#12 marked on them, and the blue have #14-#16 marked on them. Is this based solely on the size of the hole for accommodating the wire, or is it based on current ratings. I have looked up several on the web, and it seems to be related to size, since I didn't see specs for current rating.

So, if using #12 wire from PDB motor controller, is it 'legal' to use blue connectors if they fit and crimp tight? Or can that get flagged as illegal during inspection?

Thanks