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Pete,
Using gated rainbow for matrix adjustment can't get you there, because you need each color to have the correct luminance as well as chroma to see if the final R,G,B drives are correct. You can use the gated rainbow to check the phase (and maybe preliminary gain) of I and Q, but not much beyond that If you can get a generator or a DVD with regular color bars (White, Yellow, Cyan, Green, Magenta, Blue, Black), that is best. All is correct when the individual red, green, and blue outputs of the matrix are square waves. All the peaks (max and min) in one channel should be the same amplitude, but the three channels will have different amplitudes depending on how much drive the CRT requires to make white. With non-rare-earth red, this probably means red needs 2 times (or maybe more on the 15G) the drive of green or blue.
Have you ever seen a setup done with a blue viewing filter? This assumes the matrix is correct, and adjusts hue and chroma so all the bars containing blue have the same blue amplitude. If the matrix is not correct, tough! - the red and green will be off when the blue is correct. In the case of the CT-100, it's worthwhile to check all three colors, since you have internal matrix adjustments. You could do this check with red, green, and blue filters. However, if you have full matrixed R,G,B driving the CRT, you can check with a scope. This measurement (and adjustment) is not directly available on later sets that matrixed by putting Y to the cathodes and color differences to the G1's.
Regarding brightness of colors: When a true NTSC tube with nominal NTSC matrixing is used, the reds may be darker than a modern set. This is because the modern set overdrives the R-Y to make up for the smaller difference between the red and green phosphors. In other words, turning on the modern green is like adding a little red to the picture, so the R-Y gain is increased to make the red turn off a little more than normal. On strong red color, this goes too far the other way (because of the CRT gamma), so strong reds come out over-saturated and over-bright. How much of this you see depends on how much R-Y boost the particular manufacturer thought the phosphors should have for best flesh tones and average scene content. On the opposite side of the spectrum, the 15G should show more saturated and brighter cyans. This should be obvious on full color bars along with the more "green" green.
In PAL, and in HDTV, the matrixing at the camera is changed to get the right color-difference signals for the MODERN phosphors with a nominal NTSC electrical matrix. So, reds are no longer overly bright, but of course you can't get the purer green and cyan that you could with real NTSC phosphors.
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