Jeff and Harry, thank you for the fine compliments!

The pictures are pretty cool, Morgan, but that tobacco filter displays quite a bit more than a just "slight" effect. That would be quite the sunset if the colors were real, but the sun is roughly three hours from setting here and the clouds should be gray. The thing that makes them not work very well for me is the warm sky and the neutral foreground. If the sky were that colorful, it would also have a pronounced cast on the ground. You may not have been going for the natural look, though, and as long as you like them, that is all that matters.

I would suggest adding all filter effects in Photoshop except for a polarizer (which is the only effect that can't be duplicated with software) and a graduated neutral density. It would be unfortunate to be stuck with this color on the original if you ever preferred a natural version of the scene down the road.