Why do clothes look darker or change colour when they get wet?

Clothes look darker or change color when wet due to the way water affects light absorption and reflection. When fabric is dry, the surface reflects light differently than when it is saturated with water, which can cause a darker appearance. Additionally, the water can alter the way dyes in the fabric interact with light, leading to changes in perceived color. This phenomenon is primarily due to the increased saturation of the fibers and the refractive index of water.