This is a little counter to the point of the board, but I'd like to put in a vote for the example from the sticky to actually not become reality. Point 2's example contradicts point 4's rule.
I think the site's color scheme ought to be fully or widely customizable for all users, for the sake of accessibility- I've seen a few people now saying that they've had a hard time getting into it because the color scheme is difficult to look at and there's no dark mode or anything.
THAT BEING SAID, it could be fun to have cohost plus benefits give you other site theme elements to play with. A couple of fonts available to basic users, a handful more if you subscribe. Different theme shapes to recolor, ordinary cohost VS looks like an operating system cohost VS eggbug theme park cohost. Custom cursors. Move tags into the beige. Upload your own whole entire site-look, even. The kind of thing that would appeal to plus's target market (people who use the site frequently, and would be more likely to want to customize it/change it up) without making basic users feel like they have to pay for something vital. And if you do want to restrict the full color spectrum, maybe make a healthy range of preset color schemes available rather than keeping people locked into the Cohost Brand Mulberry Pie (not to diss the mulberry pie i quite enjoy it myself), for the sake of rule 4 as well as ordinary accessibility.
tldr: paywalling colors is an adobe move (literally), but paywalling funny cursor isn't
I'd suggest this. Some default free site themes. Basic default, high contrast for any disability, and dark mode. Maybe even light / white mode so it looks like a innocent website for any coworker passing by who might see your computer screen.
If you want custom themes that you or others made which change the dashboard or front facing blog on the .com/blogurlgoeshere, pay the Plus fee.