Links should always be blue and underlined

So you thought it would be clever to make your links pretty? Don't do it! If you're short on time, follow these simple rules:

• Unvisited links should be blue and underlined
• Visited links should be purple and underlined
• Active links should be red and underlined

Searching for "links should be blue" turns up enough reading for an afternoon. This is a topic that has been discussed to death, but still isn't widely understood.

How to break the rules.

Breaking the blue link rule without understanding it makes usability a disaster.

There are a few good places to break the rule though. Navigation,  Buttons, Blog Item Headers. You need to be sure to communicate the right information to your users. A good place to start understanding links is Smashing Magazine's  "The Definitive Guide to Styling Web Links"

Rules are meant to be broken. Do it in a way that considers the rules rather than confuses people.