What stellar population dominates the color of a "red and dead" galaxy?
Answer
Older, cooler, redder stars
Red and dead galaxies have largely stopped forming new stars, resulting in a population dominated by older, cooler stars that emit light shifted toward the red end of the spectrum.

Related Questions
What causes the blue light observed in actively star-forming galaxies?What stellar population dominates the color of a "red and dead" galaxy?What structural characteristic defines a "red nugget" galaxy?What does the highly compact nature of red nuggets suggest about their star formation efficiency?What term describes a galaxy that appears red but might temporarily pause star formation rather than permanently ending it?Which telescope identified red spiral galaxies, challenging the simple 'red and dead' evolutionary path?What mechanism, observed using the Chandra X-ray Observatory, can shut down star formation besides gas exhaustion?How must the light from faint, distant red galaxies often be observed due to cosmic expansion?What combination of properties provides the strongest evidence for classifying a galaxy as 'dead'?What term is used to describe the smaller, more ancient cousins of 'red and dead' galaxies?What term is evoked when astronomers refer to galaxies that have largely ceased forming new stars?