As a rough estimate, the Sun will be a red giant for about a billion years.
the red giant phase is about the end of a stars life. it will last for about one million years.
No it will not. When it dies in around 4 to 5 billion years. It will collapse into a white dwarf star and the further collapse into a black dwarf star
The Sun has always been classed, chromo-fashion ( Color wise) as a Yellow Star. one might poetically talk of golden sunshine, etc. a Red Star or sun is quite different and actually produces less heat...
About 250 times greater than it is at the moment, or about the size of Earths orbit. 1 AU.
