RGB Color Channels

In addition to monitoring your video's luma and chroma levels, you must consider the three color channels that mix together to make the frame: red, green, and blue (RGB). Video color correction is inherently tied to these three color channels. Setting the Program Monitor's Output drop-down menu to RGB Parade lets you monitor the values.

Toggle your Output mode to RGB Parade before you color correct so that you can see which color channel has the most emphasis in the image. Knowing the dominant color channel can expedite the color correction process by giving you some inkling of the correction you want to apply. For example, if your image looks too warm and upon analysis you find that the red channel is quite dominant, you may want to color correct specifically within the red channel to lower its brightness and saturation, or you could increase the value of the blue channel to "cool" off the image. For a cool image with lots of blue, you can increase the red channel a bit to "warm" it (see Figures 22.2 a and b). As you then make corrections, take note of how the channels increase or decrease in height or thickness in RGB Parade.

Figures 22.2a and b. By monitoring your footage in RGB Parade Output mode you can see the strength of each color channel in the image (a). Checking the height of the line on the right of the panel, you can see the color data here shows that the blue channel has the most strength. After you make a color correction to the red channel, the RGB Parade display updates with the results (b); notice that the red channel has increased amplitude

Of course all of these corrections are not as simple as I am describing, but the essence is exactly how it reads. With Premiere Pro 2.0 there are RGB color channel correction tools that can do this type of job quite easily.

To make color correction adjustments specific to the color channels of the image, you should be using either the RGB Color Corrector or the RGB Curves effect. Both of these effects have deep adjustment capabilities that can offer very subtle and practical results.