Why don't we see purple stars
Purple and green star exists. For example, a blue supergiant star can have its surface temperature to 50000 K, which peaks at purple in the blackbody spectrum. However, our eyes are more sensitive to blue than purple, and the contrast between blue and purple in the spectrum is insignificant, therefore we see blue.

Also, check this article: https://parade.com/295384/marilynvossavant/can-stars-be-green-or-purple/