A while back I posted about the GUI version (https://news.ycombinator.com/item?id=15087244) but I’m realizing the CLI tool is probably more appropriate for the HN crowd.

Themer is a set of npm packages that allow for generating custom, matching themes for many of your development tools (editors, terminal emulators, desktop/device wallpaper, Slack sidebar, Chrome theme, Alfred, etc.). A custom color palette can be used, or there are a number of pre-built palettes to choose from.