For some time now, the way faces are handled in identica-mode has bothered me. Basically, you set the background in a defcustom'ed variable. The faces themselves get created on startup, and have their attributes set when the timeline is rendered. One effect of this is that customize-face on those faces is ignored.

I've removed those defcustom'ed variables, and replaced them with defface'd faces, with the same default values. IMO, this is more consistent with normal face usage. The only loss, I think, is that it may be less visible to users who (customize-group 'identica).

I'd like to replace the merge-text-attribute calls with just setting the face, so that you can customize any attributes of the face and have it be applied properly, but the docstring on merge-text-attribute suggests that it's not that simple.