The colors (and maybe fonts) of ui elements in the auto completion (popup window and description window) should be configurable to match those of the RSyntaxTextArea the auto completion is installed to.

From what I see it is especially the cell renderer in the completion popup that uses some hard coded colors that can't be changed without creating a subclass. And those hard coded colors does not fit well (in my opinion) if an alternative theme (like the Eclipse one) is used for the RSyntaxTextArea.

I assume that this library and the one containing the RSyntaxTextArea should not required each other. So it might be not possible to automatically take over the colors from the text area or add easy to use support to its Theme class.
At least the corresponding classes should be changed in a way that the colors can be set without creating subclasses. That way colors can be manually set from the theme applied to the RSyntaxTextArea.

And it would be nice if the description window would apply the same formating (fonts and colors) to the description line (or whatever the first block is called) than the popup window cell renderer.