Primary Color Correction: Color Manipulation Tools - The Art and Technique of Digital Color Correction - page 142

Fig. 4.55 After Effect's built-in RGB color balance UI.
Fig. 4.56 IRIDAS's SpeedGrade DI primary color correction controls. IRIDAS has been purchased by Adobe
but had not been integrated into its product line when this topic was written.
as the “skin tone” line on the vectorscope. Technically though, this line,
along with the Q line, which is at a 90-degree angle to the I line, are actually
the in-phase and quadrature phase lines for the color difference signals in
NTSC. What does that mean? Nothing to a colorist, so we might as well call
the top half of the I line the skin tone line—for us, that's what it's good for.
Back to our tutorial. Ignoring the color chips, the goal here will be
similar to the tutorial we did with curves. We want to use the red, green,
and blue channel sliders or numerical entry boxes in each of the tonal
ranges to color balance the gray chips. We'll use the red, green, and blue
“lift” data boxes to control the bottom of the trace as it appears in the
RGB Parade display.
Compare the waveform of the properly exposed chart ( Figure 4.57 a )
with the improperly exposed chart ( Figure 4.57 b ). Notice in the top left
RGB Parade display ( Figure 4.57 b ) the difference in levels between the
channels, with the red channel (the first cell) having higher levels in all
three tonal ranges and the blue channel (the third cell) having the lowest
levels of the three. The green channel is relatively close to being correct.
If you look at the RGB Parade display at the lower left, you are looking