I use the ‘Straightdope Dark’ theme. Usually thread titles are white unless I’ve read all the posts in that thread, in which case that thread title is grayed out. But the Category titles, on the left column of the main page on a desktop view, are always white. Today something seemed off, and I realized that all the category titles are grayed out for me. No big deal, since everything works just fine still. Maybe it’s just a design tweak to the theme. Just seems weird.
I suppose in theory maybe a category title could go gray if I had read every post of every thread in that category, but of course in actual practice that is unlikely, let alone every post of every thread in every category (I like the SDMB, but not that much).