[quote}Meaning that they had an improved red phosphor that more closly matched the blue & green phosphor in brightness value.[/quote]
I thought it was the green phosper that was changed in later CRTs. The new green was brighter, but was also a bit more yellowish. Which means that the colors rendered would be slightly wrong. And it would also mean that there would be some colors (pure greens mostly) that could never be displayed correctly, even if the color matrix circuits were tweaked to make most other colors come out right. The original phospers were selected to closely match the color response of the human eye and brain. This is called "coloremetry(sp)". when the human eye sees yellow, the wavelength of the color yellow generates a partial response from the red receptors and another partial response from the green receptors. TV cameras use optical color filters that resemble the eye's receptors response to get the red, green and blue signals. Which then get encoded into NTSC, and then decoded by your TV set circuits. The CRT's phospers create a mix of green light and red light that then tickle your eye's red and green receptors to the same levels as real yellow light would have. Then your brain thinks it's yellow light. But if you send the light from the CRT thru a spectrascope, it looks quite different than real yellow light would. Other animals with color vision with differing color receptors in their eyes would see goofed up colors on our color TV sets even though the TV set looks fine to us. But only humans buy TV sets, so it's not an issue....
