Why does a fur turn reddish when wet?

Fur doesn't actually turn reddish when wet. The color change you're observing is an illusion caused by the way light reflects off wet fur.

Here's why:

* Water on fur: When fur gets wet, the water droplets adhere to the individual hairs, creating a smooth surface.

* Light reflection: Dry fur has a more uneven surface, causing light to scatter in different directions. This leads to a more complex and varied color perception. However, the smooth surface of wet fur reflects light more evenly, making the color appear more saturated and intense.

* Pigmentation: Some animals have pigments in their fur that can be affected by water. For example, some animals have a reddish pigment in their fur that can become more visible when the fur is wet, leading to a more reddish appearance.

It's important to note: The "reddish" hue is often an exaggeration. The actual color change is subtle and often just makes the fur look darker or more intense.

So, while fur doesn't actually turn reddish when wet, the change in light reflection and the potential for pigment to become more visible can create the illusion of a reddish hue.