Here's why:

* Older Red Stars in the Center: Lenticular galaxies have a prominent bulge at their center, which is home to a large population of older, red stars. These stars are generally less massive and have already exhausted their hydrogen fuel, leading to a reddish hue.

* Blue and White Outer Regions: Lenticular galaxies also have a disk component, though it's less pronounced than in spiral galaxies. This disk contains younger, hotter, and more massive blue and white stars. These stars are still actively fusing hydrogen and emit a blueish light.

Lenticular galaxies bridge the gap between elliptical and spiral galaxies, possessing characteristics of both. They are classified as S0 galaxies in the Hubble classification system.