Ok, here is a stupid question, I set CSS as hover, link and visited on my page

link=blue
hover=red
visited=grey

My question is, I want the link change color to red even if that link is visited. As I setup above, if the link already visited, it won't change color when hover it, meaning it stays as gray still. How can I make it change color when mouse over even if it get visited? please, please help.