When they are having problems with your site, which will happen at some point, the link Home provides their first lifeline back to a safe spot. Furthermore, once people recognize that they are consistently offered a way Home, they are more likely to feel comfortable in venturing forth to other parts of the site. When users can't find Home or a better navigational path, they use the Back button. However, many people find the lack of Home to be very annoying, especially if they have to hit the Back button several times before they become comfortably re-oriented on the site. Plain old hyperlinks work best.
Every novice knows what a simple hyperlink looks like.
In contrast, people sometimes fail to recognize when an image is serving as a link. Clearly identify themselves as links to pages already visited. The value of the purple hyperlink is subtle and under appreciated by many web designers. Customers use the purple color to help them find links to pages that they liked before. When looking for a new page, they also use the purple color to ignore links to pages visited previously.