I think its important for everyone to remember that it may not be the sun that is changing, but our atmosphere.

In space, and from space, the color of the sun has always been a perfect solid white. The only reason we ever saw it as yellow was because the blues/purples of the sun's light were trapped in the atmosphere, thus creating a blue sky... essentially filtering the light.. why do you think clouds are white for example? they absorb the entire spectrum of the sun's light and reflect its natural color...

its possible that our atmosphere is thinning due to pollution or chem trails, or whatever you believe, and thus more of the natural light is getting through.