disappearing doesnt neccessarily mean the plugin isnt compatable (especially in this instance). It means you need to edit the colors most likely.
I'll bet if you look at your source, the output IS there.
a WoW plugin inst going to be work or not work depending on what theme you are using. Thats a "3rd party plugin", they typically couldn't care less what theme you are using.
Suggestions: sure, get acquainted with CSS, look at your source, see what the plugin is outputting, see if it's adding CSS to your site. If it is, edit it, inside the plugin, or through whatever is responsible for the colors (external stylesheet, whatever).
Rocketscience this isnt.