Why are giant stars red, and smaller stars white or blue?

This is not true. Red dwarves are the most common type of star around - perhaps as many as 75% of the stars in our galaxy are of this type. They are small (have a mass typically less than half that of the Sun) and are quite red (in fact most of th... read more

Most dense = blue, then comes yellow white then red. since giant things are more likely to be less dense ( less tightly packed with particles ) then giant stars are most likely going to be the color of the least density ( Red ) and smaller stars are probably going to be blue. there are some rule breakers though siries b is quite large but is still blue. read more

Essentially, the differences between a blue giant and a red giant are the age of the stars and their permanence. No blue giant remains a blue giant; it eventually will turn into a red giant. read more