This was caused by a cleaner that contained Clorox bleach in it. Chlorine bleach is a strong oxidizing agent, and reacts with the acid dyes in Nylon and wool carpet. It cannot be cleaned out- the color is gone and has to be replaced.

The process requires first cleaning the carpet thoroughly, then neutralizing the bleach. Once that is complete, the dyeing process can begin. This repair was relatively simple, and was far cheaper than replacing the room.