http://sn.1w6.org/file/mk-20150528T131516-h9cdglb.html

@bobjonkman well, I finally got it working but that was *quite* involved; *I* was loading the parent stylesheet and it's 'dark' stylesheet, followed by my own child-theme stylesheet (I actually got that right) - but WP was then loading the 'dark' stylesheet *again* outside my control - and (apparently because that was not 'enqueued' I could not remove it either. I had to fiddle with priorities it get the "extra" 'dark' stylesheet first, followed by parent stylsheet, dark, and my child-theme stylesheet - so 'dark' was no longer overriding mine. And then I had to use quite precide selectors (including :not()) to select either a comment by postauthor (class) or a comment by someone else (no class) to give them different styling... #phew More tweaks to do, but I'll have to write this one down!