Erik, Most all of any paint transfer is going to come from the polishing steps. Once you have the paint corrected not much more should lift. If it does it should almost completely wash out if your washing the pads and towels correctly, if there's any staining left it shouldn't be of any real concern as it will be just that; staining, not ruined towels. MSS, QS, Americana and Buttery are all layed down onto the paint, not worked in like "Old School" waxes: so not much, if any, color should come up. As stated above DS wouldn't have any issue since the detail spray is being sprayed on your LSP not on the paint itself. What color is the car? Red is by far the worse I've worked with for color transfer, but still I just wash the towels and continue to use them with no concerns.
Oh, and to follow up on my post #10. The Toyota Sienna Van came out nicely. I used the three pads; green, orange and white that were used on the red Ford Truck back in early October with no issues at all.