Teacher:Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
Teacher: Now, understand the problem? Solve this instance: You call egg-shaped galaxies, which are reddish to yellowish in color because they contain mostly old stars, elliptical galaxies.
Student:
What do you call egg-shaped galaxies, which are reddish to yellowish in color because they contain mostly old stars?