For Internet Explorer 8 (IE8) I'd like to use the following CSS:
color : green;
I would like to apply a hack which only affects IE8, not to IE9, IE6 and 7.
Use conditional comments in HTML, like this:
<!--[if IE 8]>
<style>...</style>
<![endif]-->
See here: http://www.quirksmode.org/css/condcom.html
You can test for IE versions reliably and also be sure other browsers won't be confused.