If its the issue I think you are describing thats from using relatively low quality viewing panels in the Macbook Line, while saving the good stuff for the Macbook Pro line.
That isn't particularly an issue as much as its just not the premium option.
Its a serious issue for designers and such who rely on color. Don't ask me why they would be designing on a Macbook (non pro) in the first place, but ultimately the colors will shift depending on which angle you are looking at and can vary from even a few Cm. Most people I know don't actually sit in the same spot all the time; i know I don't. From the bus to the train to my desk(s). All different angles. But thats why I have a Macbook Pro.