So, I added a wash of white acrylic paint to the area to get it lighter. Now that it is dry, I can go back into that rock to give it some form. The acrylic white will act like gum arabic to seal the surface—in theory.
The warmer rocks that I added to balance the temperature worked well except for the value. I scrubbed the area first to get rid of some of the blue that was there. Scrubbing removed any internal sizing and the pigment is absorbed into the paper. I had to put 4 washes to get it right. I even put some gum arabic to seal the area! So, if you ever try using the Khadi paper, keep in mind that it will be very interesting to work with.