The Managers where I work tend to want to redesign the website every year or so. Different layouts, color schemes, etc.
I think they look at it so often they want to freshen it up and give it a new look.
I personally think it is a bad idea to change the color scheme because there is so much involved when doing this for a huge site. You not only have to change the CSS files, but any image files that are used for layout, any flash content, etc. Otherwise you will have many element with the old color scheme and not matching the new color scheme.
What do you guys think, would a fresh new look every year, be beneficial or are there ways it could hurt you? Is it worth the effort?