* Alpha Centauri A and Alpha Centauri B are the two main stars. They are both sun-like stars, meaning they are both yellow dwarf stars (spectral type G).

* Proxima Centauri is the third star in the system. It is a red dwarf star (spectral type M). It is much smaller and fainter than the other two stars, but it is the closest star to our Sun.

So, while the brightest star in the system, Alpha Centauri A, is a yellow dwarf, the system as a whole is a triple star system with a mix of spectral types.