Disclaimer right up front: I have no privileged information or special authority. I don't know when, or whether, the results of this question will be used. But I want to start collecting input.
The new site design has rolled out to all sites on the network, which means that SE can now customize the look of each site. Obviously there's a long list of sites to do, but a CM said they'd probably do them in order of age, which puts us fairly early on that list.
This post on Meta SE outlines the things that are customizable. The most visible design elements are colors, the logo, and the header graphic. The header graphic, in particular, can be anything from scenic art (1 2 3) to banners (1 2) to more abstract patterns (1 2 3). Logos can be lots of things, so long as it's possible to do something favicon-sized as well as something larger.
If we are able to get some design customizations, what would we like to see? How do we reflect the range of content that Writing SE welcomes?
SE is starting to work on designs for graduated sites now. This meta post on one of them gives us a preview of how they'll approach communities. We're in line behind a bunch of other sites, but read that post, think about how you'd answer it for our site, and share your thoughts in answers here.