Still messing around with this and open to feedback! I think it’s possible for users to toggle it individually. I can’t turn off the grey text for visited pages, which is too pale for my liking. Nor can I turn off pink-as-backgrond-colour for some notification boxes. But if there are other suggestions, go for it! I’m still learning what can be changed, and how.
EDIT: Have now learned how to change those, and have changed that pink to an orangey yellow.
Eventually we should make a site logo of some kind. The software can put one where it currently says “Cosmo Canyon”. And anywhere you see that grey scribbly speech bubble. Not sure if we can display a goofy tiled background image. 
And we probably can’t have a midi that automatically plays on every page, or confetti for the mouse cursor. But we should check. 
Edit: ah, it’s all super customisable, just requires much knowledge of Discourse themes. But if anyone wants to get into that, there’s a lot we can do to make this place look cool and unique!
The current layout makes it harder than necessary to find topics if they’re slightly older. Looks like we’ll try some different layouts over the next few days.
Added a user-selectable sunset theme (it’s a community theme called geometric something or other), and working on the ability to insert gifs, though it’s not configured yet. They will be set to allow even r-rated gifs but if you spam with pornographic gifs they will not be set that way for long. We just assumed gifs might be marked as r-rated for no reason.
Gifs should now be enabled!
Now with 100% more sunset!
Welcome screen always displays a human hand. It strikes me that this excludes other species. Perhaps we should find a way to include, in the randomized selection, an image of a paw.