The world has a blue hue due to the colour of the sky, it's something I'm playing with at the moment, it works really well, it just needs tweaking to make it right. The skybox is scanned and an average hue is taken from that and applied to everything, this means if you have a red sunset everything has an orange tint to it, it's generally effective, as I said... just needs tweaking to make it right!
If you take a look at THIS thread you'll see it working with other sky boxes.
If you take a look at THIS thread you'll see it working with other sky boxes.