I know there was talk several years ago about Paramount doing preservation on some of these titles.
TRIGGER JR. was done from the color elements and I'm told it looks fabulous.
This page has accurate technical data but the frame grabs are poor The original prints are not green. They also list Cinecolor being used in the late 50's on some TV shows and that's wrong. The labs were closed for good in 1954.
http://zauberklang.ch/filmcolors/timeline-entry/1297/#/...
The sad state of the Roy Rogers Trucolor 35mm nitrate elements is described in the second article on this page:
http://captainbijou.com/inc_captainsblog-08-25-2007_revised.php