Apple Color 1.0 - Manual (Page 179)

Chapter 9 Primary In 179
If, afterward, you adjust the Shadow or Midtone contrast sliders to lower the shadows,
you’ll find more of the image becoming affected by the same color correction, despite
the fact that you’ve made no further changes to that color control.
This is not to say that you shouldn’t readjust contrast after making other color
corrections, but you should keep these interactions in mind when you do so.
Using Color Balance Controls
A color cast is an unwanted tint in the image due to the lighting, the white balance of
the videocamera, or the type of film stock used given the lighting conditions during
the shoot. Color casts exist because one or more color channels is inappropriately
strong or weak. Furthermore, color casts aren’t usually uniform across an entire image.
Often, color casts are stronger in one portion of the image (such as the highlights) and
weaker or nonexistent in others (the shadows, for example).
If you examine an image with a color cast in the Waveform monitor set to Parade, you
can often see the disproportionate levels of each channel that cause the color cast
when you examine the tops of the waveforms (representing the highlights) and the
bottoms of the waveforms (representing the shadows).
Note: For clarity, the Parade scope is shown with the tinted red, green, and blue
waveforms that appear when Monochrome Scopes is turned off in the User Prefs tab.