User blog comment:Echo 1/Project: SPARTAN II/@comment-124.179.212.43-20110613080849/@comment-2026417-20110613144901

Phase 3 simply uses a new Bohrok shield for the visor (as the original was being used on another MOC), and its greener, even though the phase 2 visor is more true to the MJOLNIR armor schematics.

(Visor, in this context, is the top of the head that juts out, blocking out a little sunlight, and not the part of the helmet you look through.)