This very simple piece of CSS will change the colour of selected text, the default is usually blue. You can see this in action on this website, try clicking and dragging the cursor over come text and you will notice that it is orange! As you may have guessed, this working on most browsers but definitely not IE!!
::-moz-selection{background:#F69E06;color:#fff;} ::selection {background:#F69E06;color:#fff;}