Change "Visited" hover over color?

This might be a "Plugin Support" question, but I'm not sure. On this page: http://www.fixcoffee.net/store/products/
I have a list of all my products. On the first visit, when you hover over "Choose Options" the link turns orange. This looks great. However, after you've visited the page, the link changed to "Visited", right? And now it turns grey. The problem is, is that it blends in with the background of the container and you can't see "Choose Options" any longer.

I know I can use CSS to change this, but I'm not sure what tag to use. How can I make the hover stay orange whether the link has been visited or not? Thank you.