When I was looking for pictures of the CTC-4 clones, I got near the bottom of this page:
http://www.earlytelevision.org/21_inch_color.html
and saw the Sylvania "Granada" and "Saratoga" which both have very nice white, sort of halo-light looking masks, and got excited thinking that they might indeed have used halo-light on some early color sets... darn!
jr