Tracking stains are usually limited to the tips of the tufts. Where tracks come from could indicate the cause. Different chemicals react differently to different colors and dyestuffs. As we have noted, they also react differently under various climatic conditions. In general, red spots on tan or beige carpet may suggest strong acids.
Yellow stains indicate reactions caused by strong oxidizers or bleaches.
Green or blue stains may indicate sunlight combined with a catalyst. In general, once a textile product has been chemically stained, there is little that can be done by the individual to restore the material to its original color and condition. If a stain has occurred, the source of contamination should be identified and steps taken to prevent further contamination from the same cause. The homeowner can prevent spots from occurring in the first place by showing proper respect for household chemicals and treating them with due caution. Consult a professional cleaner.