I am red green colorblind (as are almost 10% of your Caucasian male users. I cannot see any difference in the colors used for an active click-able link I have never visited, and one I have. It would be very helpful if the default colors were shifted farther apart (visited links darker than unvisited links by at least 10%). For example click-able links never visited blue, and links I have visited purple. Pale pastel colors are particularly difficult for RG colorblind to discriminate so make the difference bold (or create a "colorblind friendly"color pallet for features which are color keyed.
Alternative option would be a setting in options to specify your browser default colors for those two categories of links.