Stars are colorful but the rods in the human eye that help process very low light intensities aren't color sensitive. The colors of the stars, though, are real, in that if you had enough brightness you'd see the colors with the cones in your eye.

If you put a very colorful picture on the ground but illuminated it with only faint moonlight, your eyes would struggle to see the colors on the picture, despite the fact that the colors on the picture are objectively real, with real pigments that actually represent colors that would be seen you had more light.

So merely pointing out the deficiencies in the human eye don't actually prove that the colors aren't real.