Which of the following factors does NOT influence mould growth?

Mould growth is primarily influenced by environmental factors that affect its ability to thrive. Among these, temperature, air exchange, and moisture levels are critical.

Moisture is essential for mould growth, as mould spores require water to germinate and flourish. Similarly, temperature plays a significant role; most mould species thrive in warm environments, and extremes in temperature can hinder their growth. Air exchange influences the moisture content of the air and can help remove spores or promote drying, further impacting mould proliferation.

The color of walls, however, does not have any direct influence on mould growth. While certain colors might have different thermal properties or aesthetic outcomes, they do not affect the fundamental environmental conditions that allow mould to grow. Therefore, the color of walls is unrelated to the biological factors that contribute to mould development, making it the correct choice as the factor that does not influence mould growth.