I'm sorry. I quit using Adium in favor of iChat 4.0, so I won't be working on any Adium add-ons now.

Thank you. You need Adium 1.0, currently available from http://beta.adiumx.com/

In the Messages preference pane turn on the "Use custom background" option, then click the color well to show the Colors window, which contains an Opacity slider.

Can you describe in some more detail the problems that you're having? I'm not aware of any problems with font colors; however, the current version doesn't support font sizes larger than 10 pixels.

Thanks. You'll find that variation in the upcoming update.