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These cameras typically used a single vidicon tube with a color stripe pattern that consisted of yellow stripes on one diagonal angle and cyan stripes on the opposite diagonal angle. You then got red and blue signals modulated by the stripe frequency, and they could be separated by a comb filter because of the opposite angles. The low-pass signal (minus the stripe carriers could be used as the luminance. The electrical focus had to be even across the faceplate, or the white balance would show a shading from magenta in the well-focussed area to green in the poorly focussed area. Because the vidicon has a built-in non-linear "gamma correction" characteristic, the red and blue signals would be modulated somewhat inversely by the luminance, resulting in somewhat poor color rendition - generally green saturation was weak and red and blue were emphasized. As circuitry got more sophisticated, the color was improved, but when CCD pickups came out, picture quality made a giant leap forward in color quality, lower noise, and no smear.
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