I’ve been cooking up a branch with theme support so I can do Brainfood branded internal tooling. As a test theme I’ve been using NeXTSTEP/OpenStep branding guidelines because they are robust and either open or effectively abandoned. I’ll push a public branch after a little more review.
I was thinking I’d do KDE Plasma next, complete with KDE icons. I don’t know if we want something like WordPress’ theme discovery feature but, if we did, we should miserably complicate our lives by decentralizing it using IPFS or something like that.