Question

What do you call egg-shaped galaxies, which are reddish to yellowish in color because they contain mostly old stars?

Answer 1

elliptical galaxies

Pictured below is a typical elliptical galaxy   Figure below  . As you might have guessed, elliptical galaxies are elliptical, or egg-shaped. The smallest elliptical galaxies are as small as some globular clusters. Giant elliptical galaxies can contain over a trillion stars. Elliptical galaxies are reddish to yellowish in color because they contain mostly old stars.