Bastardization of "Color Frame," sometimes abbreviated as "CF." Exactly as it says, an enclosure for holding (usually plastic, polyester or polycarbonate) color media, most often made of thin-gauge steel or aluminum (though lightweight, semi-disposable cardboard/fiberboard ones are available. Link to one source).
City Theatrical: Color Frames
A handy reference page: Altman Color Frame Sizes
Another more comprehensive, but somewhat out of date: http://www.mts.net/~william5/library/cframes.htm
Synonym: gelframe.
City Theatrical: Color Frames
A handy reference page: Altman Color Frame Sizes
Another more comprehensive, but somewhat out of date: http://www.mts.net/~william5/library/cframes.htm
Synonym: gelframe.