Good web site design delivers information to the user in the clearest possible way. A web site that forces user to click through unlabeled graphics to get to some content is not well designed (yet some artists love using this method). A web site where difference between a regular text or link isn't obvious is not well designed. A web site with no structure or hierarchy is not well designed. Your concern is to make all the text on the community easy to read (this means picking a neutral color for the text background and text color of sufficient contrast), making navigation bold and clear, and organizing content in a meaningful way. You have absolute freedom in choosing the colors and graphics to decorate your web site, as long as these conditions are met.