If this paragraph is orange and has a dashed border (for you colorblind folks), then you are in IE 7 or 8 (greater than IE 6 and less than IE 9).
The following method was used:
<!--[if (gt IE 6)&(lt IE 9)]><link rel="stylesheet" href="red.css" media="screen, projection"><![endif]-->
Absolutely all other browsers will not load orange.css.
This works as a technique to include CSS, JS, and other content.