There are 2 repositories under netnewswire topic.
A crowd-source themes directory for the NetNewsWire RSS Reader. https://netnewswire.com. Hosted at https://nnw-themes.xyz
Theme for NetNewsWire, inspired by sspai.com. 少数派风格的 NetNewsWire 主题
NetNewsWire integration for Chrome.
I cannot stop making color themes styled after Things 3.