A product from Sherwin Williams called "woodscapes" is a stain that is applied to shingles (cedar or any kind) to preserve and add a color. The product even comes in clear.
The down side is that you must apply this with a sprayer and the first time it really absorbs the stuff. From then on, it is like painting a wall.
Here in Texas, we use that alot especially on eaves. The heat and sun really dries this out and causes it to curl. But if you maintain the shingles and use this preservative, it will really assist you, especially with new shingles.