[kh99]

OK, you can make the replacement include a background color, like:

<span style="text-indent: 20px; background-color:blue">{param}</span>

Maybe you want the background color an option on the bbcode, which you could do, but with this replacement it would allow a user to put whatever css attributes they want in there, which might not be good (you could for example use absolute positioning to put something anywhere on the page you want). It might be possible to use an old pre-css attribute to set the background color and avoid that problem (although I don't remember if there is one or what it is).