Windows 7, Hyperlinks in red and blue

I have been trying to change the "longevity" of my hyperlinks. If one goes to "tools" on the toolbar, then to "options," then to "privacy," the fourth line down asks how long the computer should keep the "history" of used hyperlinks. When one clicks onto a hyperlink, it changes from blue to red. There is a box on that fourth line in which one can determine how many days this link should stay red. I have put various numbers in that line and nothing happens - everything just stays red. The last number I put in was "15" - intending that the links should stay red for only 15 days. All of the links have stayed red since last February. Am I doing something wrong?