If you could make a new portal gun model as well as model some circular, disc-like portals, that'd be great. Just make the parts that can change color use a transparent texture or whatever.
As far as the portals themselves I was thinking they could be hexagonal just to stay low on polygons, and make the outer rim raised a bit and transparent, with the center either black, white, or transparent.
If you do this I'll work them into the current portal gun add-on which I've made a bunch of modifications and improvements to and you can have it/preview it before anybody else
and I would also love you