[old_tv_nut]

What do you mean by "100%?" Is that just cranking the color knob to max? That obviously should be too much. If you cannot judge the setting by the look of skin tones, then there are more technical ways involving color bars while viewing through a blue filter. For that you will need a DVD with color bar pattern and a blue optical filter.

You say the CRT may be weak. Does the red gun bleed when you turn the color all the way down but turn the contrast to max? If it does, you have to reduce the contrast to eliminate the bleeding, and reduce it a bit more to allow for bright reds. If a black and white picture doesn't bleed at max contrast, the CRT is probably good enough, you just have to avoid overdriving by using somewhat less contrast and the right amount of color.

Because of the color difference gains used in NTSC sets to compensate for modern phosphors and get proper skin tones, the red is driven the hardest of all saturated colors (and also possibly harder than blue or green to get grayscale tracking), so red is usually the first color to show bleeding problems.