A while back (probably years) I saw a tutorial on making a video b/w but leaving one color.
I can't seem to find it anywhere on the web, (I'm probably not using the correct verbage in the search).
Does anyone know where I could find it. I think that you use 'Color Correction (Selective)' portion in the Control Tree.
The tutorial I remember was of a roller coaster, the video was stripped of all color except the roller coaster which was yellow (I think).

John