Kind of a What if thing but If earth grew under a red sun and we sent a person to live under a yellow sun what would happen to them?

The short answer: it depends.

Humans are a product of evolution and natural selection. We evolved skin as a protection against UV radiation, but we also need some of the Sun's radiation to support some metabolic processes. Also, our eyes work well with the light produced by our sun.

And in an indirect way, we evolved to eat certain plants that thrive on our Sun's light. Animals that we eat also eat some of those same plants.

So what would happen to a person that evolved on a planet with a red sun? Maybe nothing. Maybe they'd be blind. Maybe they'd starve. Who can say for sure?

They'd get really sunburnt and maybe end up with visual damage from accidentally glancing at something brighter than they evolved with. Ditto for how you or I would do under Sirius or Vega ("blue" stars).

What if a black person from Earth went to the poles of a planet orbiting a blue star? You know, blue star Scotland.
- I couldn't actually tell you how much worse the sunburn problem would be, exactly. On top of the new blackbody spectrum you'd have to account for the influence of the atmosphere, which is actually a very complicated problem even on Earth, and then find detailed data on the sensitivity of human skin of various kinds to various frequencies and patterns of exposure.
  
  (For an unspecified alien it's obviously impossible, although we can guess that, like all biology, it's affected negatively by energetic light without special adaptations to fight the damage)
  
  On the rare sunny Scottish days, they better stay indoors mostly or wear a mask to protect their eyes. What we're talking about is a welding arc in the sky.

Probably not much unless they're Superman

Sunburn, maybe? I'd look up the different wavelengths emitted. I don't think there would be anything like plants becoming inedible.
Haha! Yes! Then there'd be no one to stand in the way of my giant space laser extortion scheme!

Curse you, Superman!

Obvious. They turn orange.

Super powers