Nylon carpet fibers are provided which resist staining by acid dye colorants at room temperature, yet are dyeable at elevated temperatures with acid dyes without losing their resistance to acid dye colorants at room temperature. The fibers are characterized by having a coating on the surface thereof comprising one or more selected compounds (stain blockers). Carpets comprising the fibers resist staining when exposed for long periods of time to spills containing acid dye colorants. By also including a fluorochemical in the coating, the carpets can resist such staining even after being subjected to heavy human trafficking.