Improve link text coloring for some themes

[Spitefire]

You can only tell links apart from normal text on the 'Light' and 'Dark' themes

 

[FireFish5000]

+1. There is a slight coloring difference, but it is way too slight.
I would be using the abyss theme if I could tell links apart. For all dark themes other than dark, links seem ever so slightly darker than normal text. Not enough to draw attention though. Light themes (other than light) I believe are ever so slightly lighter.