Just so you guys know, if the sun was blue, it means it has to be really, really hot.
Our sun is just about 6000°C but for a star to emitt more more blue light it needs about 40000°C, basically everyone on the planet would be roasted instantly if it's that big on the sky.
If somehow everything is heat resistant, UV radiation would give everyone cancer and rearrange DNA randomly.
But even if everyone is fire and radiation proof including mc, his natural sleeping schedule since blue light suppresses melatonin levels in body.
Even if everything above were still somehow not effecting mc, the light wave is extra damaging to our eyes, it's something a kin of "snow blindness" but vision would be blurry and eyes constantly in pain up until total blindness.
Yeah...