Which factor does not influence the R-value of insulation?

The R-value of insulation is a measure of its thermal resistance, significantly influenced by several physical characteristics of the insulation material. The density and thickness of insulation play vital roles—greater density can contribute to improved insulation properties, while increased thickness generally enhances the R-value by providing more material for heat resistance. Similarly, different types of insulation materials possess varied thermal resistance values that directly affect the total R-value.

Color, however, does not have a direct impact on the R-value. While color can influence the amount of heat absorbed or reflected from a surface, it does not affect the material's ability to resist heat flow, which is what the R-value quantifies. Thus, the correct choice indicates that color is not a factor that influences the R-value of insulation.