After googling and binging "remove neoprene scuff marks from carpet" and getting only 10 to 20 hits on either site - few of which addressed carpet - and none of those (except maybe baking soda)sound good to use on a light beige carpet, I still need help.
The soles of these SAS shoes simply started to fall apart. These shoes had been rarely worn but were only about five years old. The soles just suddenly crumbled. I was able to vacuum up most of the disintegrating soles but Mom's legs don't work well causing her feet to drag so there are three places which look like the carpet has been stained.
My parents are in a new manufactured home and the stains were not there before. I will be checking back for viable suggestions!