Web Design in a Nutshell, 3rd Edition

Colors values may be specified in any of the methods outlined in Chapter 16 and Appendix D. If no border color is declared, the default is the foreground color for the element (i.e., the text color for text elements).

The border-color shorthand property is demonstrated in this example and in Figure 19-10.

    div {border: 6px solid;
        border-color: #333 #666 #999 #CCC; }

Figure 19-10. The border-color property

CSS 2 added the transparent value that allows the background of the parent element to show through the border, yet holds the width of the border as specified. This may be useful when creating rollover effects with CSS (this technique is explained in Chapter 24), because the space where the border will appear is maintained when the mouse is not over the element.

Tip

Unfortunately, the transparent value is not supported in Internet Explorer for Windows through Version 6. Support in IE 7 (in beta as of this writing) is possible, but not documented.