This happens to me too, but with other gear like chokers and the like. All Ultima Gear which involves a red glow is now green.

I believe this is an issue involving the first dungeon of 6.0, which uses the same model for the chokers and rings dropped, but in a different color; a number was perhaps deleted/changed while adapting the ARR models to this gear and all red glows are now affected, which was of course overlooked because it's old base game gear.
It's definitively supposed to be red though, used it on all my glamour plates