Which of the following factors does not affect friction between two surfaces?

The color of the surfaces does not influence the friction between two materials. Friction is primarily determined by factors such as the roughness of the surfaces, the weight of the objects involved, and the type of material from which the surfaces are made.

Surface roughness affects how the microscopic irregularities or asperities on each surface interact, impacting the amount of contact and resistance. The weight of the objects plays a role as it influences the normal force pressing the two surfaces together; a greater weight typically results in increased friction. Different materials exhibit various frictional properties based on their composition and texture, which can significantly alter the friction experienced between them.

In contrast, the color of the surfaces has no mechanical significance regarding the interactions that produce friction. It does not alter the physical or chemical properties that dictate how surfaces interact at contact points, making it an irrelevant factor in the context of friction.