As the frozen electron gas moves, the magnetic fields move tangling with each other. When the fields are very strong, they create pair or groups of sunspots. The magnetic cycle goes through a period of 22 years, twice the sunspot's cycle. Red color is same as color of Chromosphere and comes from hydrogen lines. These burst out around the sunspot in reaction to the blocked flow of energy under sunspot.
Solar flare is much smaller scale phenomenon than prominences.
It rises for a few minutes and decays in an hour or less. It emits vast amount of x-rays through visible radiations, along with streams of high energy electrons and protons. Corona is not quite uniform halo. It is actually made of streamers controlled by the solar magnetic fields. Long thin streamers allow charged particle to escape at 2 to 3 solar radii.