The following post is provided by John Lynn of Genius DV. GeniusDV provides Avid Media Composer Training to many locations nationwide.
While secondary color correction is a specialty of Avid Symphony Nitirs, it can also be achieved in Avid Media Composer or Avid Xpress Pro. In fact, creating the "Pleasantville" effect in these applications is a fairly simple task.
For learning purposes, find a short clip that has a dominate object that contains mostly one shade of color. In this example, the orange flower.
Start by editing the same exact clip to V1 and V2 on the timeline as shown below. Make sure the starting and ending points and each clip match up exactly.
Then, navigate to the Effect Palette and place a color effect onto V1.
After you apply the color effect to V1, click on the Effect Editor button. Make sure that you're monitoring V1, so you can see that changes that you make to V1 while in the effect editor window.
Now, drag the (sat) slider to -100. This should make the clip that is on V1 turn to black and white. The composer window should now display the clip as a black and white video image.
Go back to the Effect Palette and apply the Chroma key effect to V2.
Enter the Effect Editor on V2. Make sure to monitor V2 so you can see the changes that you make in the Effect Editor window. Before moving forward, your timeline should like like the example below.
Within the Effect Editor, you need to specify the color that you want to key out. In this case, the orange color. You can click in the key color box and drag your cursor to the composer window to pick the color you want by using the eyedropper. This will give you a good start to matching the color.
Make sure you click on (Invert key) to see the black and white image underneath V2.
The controls can be finicky. It will take some experimenting to find the correct value. Normally, it is a fine mix between the Hue, Gain and Softness controls. Once you get the correct mix, the result can be spectacular.