The sky is indeed blue..... Right?

Yet another stream of thought that seems more practically addressed via a blog than on Twitter. This time I am calling into question 'the obvious'.. I am curious as to how the light of Truth might reach one who gazes through the fog of beliefs.. Which may or may not be wrong.. I don't know if that's as far an assertion as I am willing to make.. I guess it is best that I go back and address where this comes from.

I was having a conversation with a really close friend of mine, recently. To give you a better understanding, I will say that the conversation was with regards to what people are told to believe all there lives and what they see as 'reality' in all of their days. The first example that had been used was the ever-blue sky.

This friend said essentially that we all know what the color blue is, by association, by name, by wavelength, etc. We know the color blue. And we all have been told, and can very well see that the sky is, indeed, by very definition, blue. You won't look at the sky and say, "oh, you know, maybe it's purple. Or green. Or maybe even yellow." However you look at it (or define blue, blue-cyan, or any more specific color of similarity), you know, as you well see and have infinitely been told, that the sky is blue. In fact it is not even really questioned. Such is belief, and such is Truth in the common eye of all men.

But being so eager to play devil's advocate as I am always, the very first thought that came my mind was this:

Ok. So everyone around me and everyone I've ever known has told me the sky is blue, and I have since agreed and considered this a Truth. But if someone (probably from distant lands or far away mind) suggested to me, "You know, the sky may not actually be blue - what if it appears to be blue just because sunlight refracts through our atmosphere in such a fashion that it appears blue, when really, it isn't. There is no entity 'sky' with the attribute 'blue'..." I wonder if such a simple glimpse of Light in this regard would open my thinking to the possibility that "the sky isn't blue". Or even, and I think this is important, that there's more to it than just that..

I just think that's an important question to ask.. Were someone to posit to you the possibility that there's more to things than what you see, what you read, and what you've been told for all of your days, would you shut out the ideas presented? Even if you don't fully believe them, at first- would you consider using such Light to find your way to greater, more encompassing Truths?

Another brought up the point that this person would need to provide some foundation of proof, before she were to accept it - a point I would to very large degree agree with. But what if the conversation revolved around not the sky, but religion? Is there ever enough 'proof' as to there not being a God, or that one is more real than the next? Are there ever enough facts to sway you from such belief? And at risk of being an asshole and ending this blog with a litany of questions to which I have no real answers, if you are as sure about anything as the believer is their Almighty, will any thought or theory ever bring you to change your mind?

Or will you wait until everyone else accepts it as Truth?