Does anyone know the best way to make a person black and white while the rest of the video remains in color? Is this possible in After Effects or is there a better program. I plan on doing a short film but need one person to be in black and white the whole film.
Sit down, brew a pot of coffee, crack your knuckles, and get ready for a grind. The only fool proof method is rotoscoping an adjustment layer. After Effects (CS5+) does have a rotobrush which may make the process faster for some scenes (like the character's head against a plain wall or the sky).
Alternately, consider using some green screen as well if you haven't begun principal photography.
Lets say there is a static shot of someone walking. Have someone follow them with a greenscreen on a frame. You can then shoot a rolling take of just the background. With the original shot you can key/garbage matte the actor out and then desaturate and plop them onto the background. Designing the scenes and coverage carefully so you can maximize this technique could save you weeks in post.