I think the reason is that the forum uses just one 32x32 blurry favicon:
While the main site has a set of four nice ones, at 16x16, 32x32, 96x96, and 192x192:
Anyway, while I doubt it was intentional for the forum to be stuck with a blurry version of the logo, it’s actually useful for them to have different icons, especially in the mobile browser case above, where there are no text labels. So instead of fixing this by making them match, I’d like to suggest that we adopt a significantly different icon for the forum!
Does anyone have suggestions? (And/or talent to implement them?)
Of course not, that’s the point of having this serious discussion first😀
Also, it’s just part of the logo, which already has both dark and light versions:
So there is precedent for changing at least the colors.
One idea I had was two copies of the stone, to represent a group of people meeting together. But the stone itself already has two colors, and people come together (to play games) on the other server, too, so I’m not sure whether that metaphor works.
Another idea: what about a black & white speech bubble?