I did a Cedar Brown (Alcoa) on my house by the ocean in Maine. I had no problems with it and had a whole gable end replaced like 10 years past the original install after some dimwit took the power pole down at the road and ripped the service and most of the siding off my house. I was really worried about color fade when it came time for replacement there was no issues with matching color I was very pleased.
On the other hand I have Colonial Yellow (CertainTeed) on my Vermont house and the East/southeast side has certainly somewhat faded compared to the north and west sides.
I knew someone with a light blue (can't say for sure what the the brand was but thinking CertainTeed) some years ago had the entire house resided under warranty as it had faded terribly go figure