I resolved the problem of the fawn fabric by going back to the stash, finding this piece that I had dismissed earlier as being too orange with indistinct spots.  It had areas of less orangeness, though, that I thought had possibilities.  I cut the body from an area that had nice sized spots, but on the wall they were not showy enough.  I decided to try bleach discharge with the Clorox Bleach Pen on the spots, first playing around with an edge of the unused fabric. Bleach direct from the pen ran and made the spots too big, but applied with a Q-Tip, I was able to control it and I think I got really nice spots!  I neutralized the bleach with Hydrogen Peroxide, then washed it thoroughly with Synthrapol. You can see lower on the belly, the original spots before bleach, I felt like that was good for that area to leave them alone.

I am not happy with some of the background fabrics and am in the process of changing them.