I had been able to set the mask, but could not tell what I was supposed to do to actually affect the color change. In a recent post, Boris said something to the effect of, “What I do is not so technical, I just move the hue slider until I get what I want.” That is a very loose quote.
And that led me to understand that I should go to the 4 Ways tab in the ColorBalanceRGB module. Previously, I had been trying to move the sliders in the Mask tab.
I am an old man, and I learn more by reading than by watching videos. When I had been trying to study Boris’s videos, I just never made the connection to exactly what I was supposed to do.