Had anyone found a definitive way to change the background colour of the infobox yet? Nothing mentioned in this thread has worked (all the CSS indicated previously is already a different colour) and I'm getting beyond fed up with trial and error. I managed to change the username and "remove marker" text with a few CSS tweaks, but the infobox appears to be a real pain...
The obvious workaround of adding a div or span class to the mapInfoBox template prevents the map from displaying at all, as does such simple amendments as removing the <h3> tags or attempting to insert a style class within a div, p etc. I cannot for the life of me work out what the heck is going on with this.
The reason I'm trying to amend the infobox background colour is that the default style of one of our usergroups is white text, and no CSS change will override that as the element style of the {$memberData['g_title']} takes priority. Literally the only way is to either change the colour scheme of our member groups, which isn't practical, or remove the member titles from the infobox altogether, which I'd prefer not to do.