What stellar composition generally defines elliptical galaxies?
Answer
Mostly older, redder stars
Elliptical galaxies consist mostly of older, redder stars because they have largely ceased star formation, having used up or lost their cold gas and dust reserves.

Related Questions
Based primarily on what characteristic did Edwin Hubble organize galaxies in his sequence?In the Hubble Tuning Fork Diagram visualization, which class of galaxies occupies the handle?What stellar composition generally defines elliptical galaxies?What does the designation $ ext{E}7$ signify for an elliptical galaxy?Which feature distinguishes spiral galaxies from ellipticals and gives their arms a blue appearance?How does the classification of a spiral galaxy progress from $ ext{Sa}$ to $ ext{Sc}$?What is the defining characteristic of a barred spiral galaxy, such as the Milky Way?Where are lenticular galaxies ($ ext{S}0$) positioned on the Tuning Fork Diagram?Why are Irregular galaxies often described as being in a 'temporary resting place'?What is the primary difference between Peculiar galaxies and standard Irregular galaxies?