The Sun’s surface is actually blue.

The Sun’s surface is blue. The light we see from it is the light it gives off, plus the light it reflects from the surface of the Earth. The amount of blue and red depends on how much dust there is in the atmosphere, which depends on how many trees there are on Earth.

If there were more trees on Earth, then more dust would be in the atmosphere, and so more red would be reflected from the sun. This would make it look redder.