Sunspots appear dark not because they are actually dark, but because they are cooler than the surrounding photosphere (the visible surface of the Sun).

Here's why:

* Sunspots are cooler regions: They have temperatures around 3,800°C (6,800°F), which is about 1,500°C (2,700°F) cooler than the surrounding photosphere, which has a temperature around 5,500°C (9,900°F).

* Temperature and light: Hotter objects emit more light and at shorter wavelengths (like blue). Cooler objects emit less light and at longer wavelengths (like red).

* Contrast: Because sunspots are cooler, they emit less light than the surrounding photosphere, making them appear darker in contrast.

It's like looking at a piece of dark fabric on a bright white sheet - the fabric isn't actually black, it just appears darker against the bright background.

Even though they appear dark, sunspots are still incredibly hot, just a bit cooler than the rest of the Sun's surface!