Background in Hover Text

Hi, I am starting very simple in learning the Linden scripting language. I recently purchased a dog and put his name as hover text in the colors I wanted over him (he is an object). I would like to put a background behind his name as mine and other avatars appear (that brownish transparent background). I am thinking it's either an object or a texture with some transparency setting. I would appreciate any help as to what command I need and where it would be placed. I have tried so many things and I'm just not getting it to work.