Apple Final Cut Pro 6 - Manual (Page 1395)

610 Part III Color Correction and Video Quality Control
2 Click the Invert Selection button to reverse the key created by the Limit Effect controls.
The Desaturate Highlights and Desaturate Lows Filters
Sometimes, the use of one of the Final Cut Pro color correction filters results in
unwanted colors appearing in either the highlights or shadows of your image. The
Desaturate Highlights and Desaturate Lows filters allow you to target a range of the
brightest and darkest areas of your image and desaturate them, which helps to keep
the highlights and shadows of your image free from coloration.
The Desaturate Highlights and Desaturate Lows filters are actually the same filter, but
with different default settings. If you need to desaturate the highlights and the
shadows, you can apply either filter once and then select both options.
Invert Selection button
The bicycle remains red
and the background
turns into various shades
of gray.