Alright, I'm going to get this out of the way now. Colors are determined by certain frequencies' or whatever the term is, of light and what not. The color red appears for a certain frequency. Now, I may very well have my terms mixed up, but it is in fact scientifically possible to prove that the sky is in fact, not red.

People just seem to think 'Opinion' applies to anything they think. Opinion cannot be applied to something that is concrete. If something is blue, no matter how hard that person feels otherwise, it is not red. Putting 'In my opinion' in front of it simply means that they have no idea what on opinion actually is.

On that note, on opinion can in fact be wrong. I mean just look at how many people think Final Fantasy VIII was a good game. What more proof do you need?