The main factor that affects the color of a star is its surface temperature.

Quick Scoop

  • Hotter stars have higher surface temperatures and look blue or blue‑white because they emit more high‑energy, shorter‑wavelength light.
  • Cooler stars have lower surface temperatures and look orange or red because they emit more low‑energy, longer‑wavelength light.
  • Astronomers group stars into spectral classes (O, B, A, F, G, K, M), which basically sort them from hottest and bluest (O) to coolest and reddest (M), again tying color directly to temperature.

Other influences like a star’s chemical composition or motion (redshift/blueshift) can slightly tweak the observed color, but these are secondary; the dominant factor in what color you see is the star’s surface temperature.

Information gathered from public forums or data available on the internet and portrayed here.