What causes the different colours of stars?

The colour of a star is determined by its surface temperature. Cooler stars, with temperatures around 3,000 Kelvin, appear red, while hotter stars, exceeding 10,000 Kelvin, shine blue. Stars with intermediate temperatures, like the Sun, emit yellow or white light. The colour spectrum of a star also reveals its age, size, and chemical composition. By analysing starlight, astronomers can learn about the physical properties of stars and their life cycles.