Imitation and Principles

Straightforward question raised by a player who has Imitation.

Imitation: Use a Green action ability of a nearby ally (using the same power/quality they do).

Can a character with Imitation use the Principle of a nearby ally?

It's a green ability...so I can't see why not.

I'd also agree that they can it's a green ability to attempt an overcome.  

Fair enough. I wanted to hear or read someone else say it, and I'll bring the ruling through.