Crafting requirements.

[MistakeNot]

So the 50 greens are better then the 51s

So?
The best level 50 combat gear (Augmented Ironworks) is a lot better than any of the level 51 stuff.
That is the case all over the line - the top-end gear at old level caps is a good deal better than the gear you can get at the next few levels. This is true for crafting, gathering, and battle gear.
This is fully intentional and in no way a problem.