This invention relates to compositions of Bis-(N,N disubstituted-aminophenyl)phenyl methane colorants that decolorize rapidly when applied to surfaces having a basic pH, such as concrete, but remain visually apparent on vegetation and soil. These compositions can also be used as pH indicators in their colorless form by developing color on acidic surfaces or in acidic materials, such as in/on paint, ice, concrete, and acid cured polymer systems. The compositions are also useful as spray pattern indicators for landscaping, construction, and golf course applications. The compositions also exhibit reduced toxicity when compared to other traditional colorants of similar shade used as spray pattern indicators.