Hrvoje Niksic <hniksic(a)srce.hr&gt; writes: Something like that yes. I am not sure it is needed to be that dynamic. I thing adding a hook to each specifier that is called when that specifier is changed would be sufficient. Then you could put a hook on the background color specifier of the default face such that when it gets changed you simply recompute the tags, invalidate all the caches and redisplay the whole shebang. This hook could also be used to do other things. For instance imagine that the fallback value of the font specifier of a face is another specifier "font-model-font". Thus specifier is autoconstructed from the face's family, weight and size specifiers, which have hooks on them so that when they get changed the font-model code recomputes font-model-font. Jan