How is the visible color shift to red explained during the red giant phase?

Answer

The peak wavelength of emitted light shifts toward the longer, cooler end of the spectrum

The surface cooling causes the peak wavelength of the emitted light to shift towards the longer wavelengths associated with cooler objects, resulting in a visible red color.

How is the visible color shift to red explained during the red giant phase?

#Videos

What Causes a Red Giant's Surface to Cool? - YouTube

starsstellar evolutionastrophysicsred giantscooling