Apple Color 1.0 - Manual (Page 148)

148 Chapter 8 Video Scopes
The Parade scope is also useful for comparing the relative levels of reds, greens, and
blues between two shots. If one shot has more red than another, the difference shows
up as an elevated red waveform in the one and a depressed red waveform in the other,
relative to the other channels. In the first screenshot, the overall image contains quite a
bit of red. By comparison, the second shot has substantially less red and far higher
levels of green, which can be seen immediately in the Parade scope. If you needed to
match the color of these shots together, you could use these measurements as the
basis for your correction.
The Parade scope also lets you spot color channels that are exceeding the chroma limit
for broadcast legality, if the Broadcast Safe settings are turned off. This can be seen in
waveforms of individual channels that either rise too high or dip too low.
An elevated red channel betrays the degree of the color cast
An elevated green channel reveals a different correction to be made