Which factor does NOT influence the residence time of a pollutant in the atmosphere?

The residence time of a pollutant in the atmosphere refers to the duration that a pollutant remains in the air before being removed, typically through processes such as deposition or chemical reactions. The factors that influence this residence time typically include the atmospheric conditions, the chemical properties of the pollutant itself, and the number of emission sources contributing to the pollutant's presence in the atmosphere.

The color of the pollutant does not influence its residence time, because residence time is determined by factors such as molecular stability, reactivity, and the mechanisms by which the pollutant is removed from the atmosphere, rather than a physical characteristic like color. Therefore, since color has no bearing on how long a pollutant will remain in the atmosphere or how it interacts with other atmospheric components, it is the correct answer to the question regarding which factor does NOT influence the residence time of a pollutant.