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Slight reverse to what you said - The CT-100 had non-rare-earth phosphors which matched the NTSC specs. The major difference form modern sets is the "true green" Willemite P1 phosphor. For this reason, the CT-100 color rendition is "standard" but rather dim. Later, with the introduction of sulfide green (more yellowish) and then rare earth reds, the pictures got much brighter - but compensation had to be made in the color matrix in the receiver, which cannot be accurate over the full range of colors due to the non-linearity of the CRT ("gamma"). (Generally, to get the correct flesh tones, saturated reds get brightened and cyans get darkened, and hue errors get pushed to less critical colors like purples and magentas.)
Present cameras may have been pushed towards being suitable for "SMPTE C" standard phosphors (which include sulfide green and rare earth red) to some extent, even though they are used for NTSC sources. In the PAL specs, they got out of this mess by specifying NTSC electrical matrixing for the R-Y and B-Y, but camera characteristics (including any electrical matrixing before gamma correction) for slightly different sulfide green and rare earth red phosphors. The result is that colors are reproduced correctly, but some saturated cyan colors are outside the reproducible range. for example, the Newport cigarette package. (But of course, that can't be advertised on TV in the US anyway.)
Now HDTV specs everywhere are following esentially the PAL procedure, but with again slightly different primary colors. The result is that color in HD is much more predictable and correct than in NTSC. The HD specs have even been adopted as "sRGB", a default color space for digital still cameras
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