Styles all horizontal rules in the skin and Text / HTML module.
Note: The color property does not affect the color of the horizontal rule. To change the color you need to use the border property. The text-align property also does not appear to have any affect, so the color and text-align elements can be removed without any problems.
border: 3px solid green;
Here is another example of changing the horizontal rule to a 1px green rule.
border: 1px solid green;