I already said that the sun itself might not have been replaced but that something has been done so it looks different. There could be something in the air that just makes us perceive it differently. But it's definitely different than it used to be. I know I used to be able to look at it as a kid and it was a warm yellow, not the harsh white light that it is now.
If you go outside now, you can barely even look up without squinting. There's a reason that someone doesn't want us looking too closely at the sky.