TR and NC shields are both representative of their primary colour, the Elmos and Smurfs. However the Barneys' shields are teal, which isn't consistent with this. Purple shields please.
Teal has always been the secondary Vanu color like yellow for NC and black for TR. Its not a bad choice.
It also has to be a bright color so that you face the same disadvantages from using it at night. Purple simply wouldn't be as visible.
Too much of an advantage for Terrans... colorblind NC and VS would be killing their own guys since you cant ID the uniforms well enough with shield on. With teal, there is NO problem. I am colorblind, do not change this...
