The blue circles represent full transmission T=1 cut-out parts of the object, and the blue ellipses represent the object's partial transmission T<1. Credit: Physical Review Research (2025).

A star's color is determined by its temperature. Hotter stars appear blue; cooler stars appear red. Stars emit light across a range of colors, not just one. No star can emit only green light ...

An object’s color appears differently under different lighting and against different backgrounds − for different viewers. But that doesn’t mean colors are subjective.