How about the new truecolor osd VDR has now?
Well, you did ask regarding a "HD OSD" which isn't automatically a true color OSD ...
Whereas AFAIK true color OSD is also possible with SD (576i) output, e.g. xine/xineliboutput. The main problem, there isn't any real true color OSD skin out there, to use it ...
But the skins I did test, looked impressive with softhddevice :-)
Regards fnu