Coloring of individual frames by the use of very fine brushes. The process was previously applied to lantern slides. Any water based translucent dye was suited for the process, most often the coloring was done with acid dyes.
The first subtractive 2 color process introduced by Technicolor captured the incoming light through a beam splitter with red and green filters also. However, in contrast to the first Technicolor process, the two b/w images were recorded on one negative strip. This was achieved by the pull-down of two frames simultaneously, a process that required the double speed in the camera. These two frames were arranged in pairs, whereby the green record was inverted up-side down (see image).
The third Technicolor process used the same camera as process no. II to combine a pair of frames of the red and green record respectively on the b/w negative (see image). In contrast to the former process, however, the two images were printed on one side of the positive by the dye transfer or imbibition process.