These diagram explains how the color curves were changed for the best adjustment in steps 4 and 5.

Adjust the black level so that the low end of the curve for each color (R,G,B) is equal as see picture 2.

Adjust the white level so that the high end of the curve for each color (R,G,B) is equal as see picture 3.

This setup gives the best color balance.

What is the relation between the color and the brightness adjustment?

Brightness uniformly adjusts the amount of light output for the entire screen and its background. If it is increases too high the background will become white, too low and many dark colors will not be displayed. It affects all color controls.

Contrast varies the difference in light output from the lowest to the highest screen intensities. It is the brightness adjustment for the video signal area.

After making the color settings, readjust the contrast to get the best definition and intensity of the colors for the displayed image.

14 3 COLOR ADJUSTMENT