Augmented reality means displaying virtual 3D content, registered to the real world. So a 2D panel that sticks to a wall, or a 3D object that sits in place on a desk, etc. The display is "just" the way to present that content, getting the registration requires cameras, 6DOF sensors, CV, SLAM, etc.

Monochrome AR is certainly possible, and probably 90% as useful as RGB AR. I'm just saying the Vaunt hardware seems to be display-only, i.e. a HUD, without any capability to do the registration part.