Well, I finally got around to checking this out. I used the SMPTE color bar pattern on the AVIA DVD and...

Panasonic DMR-ES10 =(s-video)=> Hauppauge USB-Live2 Capture Card gives me surprisingly-close results using all default settings.

(All values given below are in YUV.)

DMR-ES10 =(S)=> USB-Live2

video_black: 16/128/128

video_white: 233/128/128

75% grey: 180/128/128

75% yellow: 161/45/141

75% cyan: 130/155/46

75% red: 64/100/210

Question: Will this method help when the values are this close?