I am in the process of changing the links on my website. I currently use font-family:Tahoma,Verdana,Arial,sans-serif;font-size:11px black text on a white background. The color of my links text is color:#031d4b. I am looking for a suitable user friendly on hover color and visited color that would blend well with this color. Any help on this matter is greatly appreciated.
Colorblindness, for the most part, can be addressed by adjusting the luminosity/shade of a color. A color blind user might not be able to distinguish between a red link and a green link which are equally "light," but would be able to distinguish dark red and light green or vice versa.
A web search should turn up plenty of sites that test for contrast between two colors. WCAG 2.0 specifies a contrast ratio of 4.5:1 for accessibility.