I think links are a pretty important aspect of many answers. However, while reading an answer (and I was rereading it for about 30 minutes), I never noticed that there was actually a link in the answer as the color is very similar to the surrounding text's color. Ofcourse, this is completely subjective, other's might be seeing it just fine, but I think overall, visually, links can be improved. (I'm not color blind or anything).
Here's a picture. (Also I must admit, after I saw it I can't unsee the dark blue, but still on my screen it's pretty hard to see). 
