The CSS Links Page Properties category lets you define the default font, font size, and colors for links, visited links, and active links:
Font specifies the default font family to use for link text. By default, Dreamweaver uses the font family specified for the entire page unless you specify another font.
Size specifies the default font size to use for link text.
Link Color specifies the color to apply to link text.
Visited Links specifies the color to apply to visited links.
Mouseover Links specifies the color to apply when a mouse (or pointer) hovers over a link.
Active Links specifies the color to apply when a mouse (or pointer) clicks on a link
Underline Style specifies the underline style to apply to links.
If your page already has an underline link style defined (through an external CSS style sheet for example), the Underline Style pop-up menu defaults to a "dont change" option. This option is there to alert you to the fact that a link style has been defined, and that you may not want to alter the underline link style. If you modify the underline link style using the Page Properties dialog box, Dreamweaver will change the previous link definition.