bootswatch

This tutorial [0] / [1] (using LESS) worked well for me. I recently did the upgrade from 3.3.6 - 3.3.7. You create a directory just outside bootstrap and reference that from `bootstrap.less` inside the bootstrap core to override the bootstrap variables. Then you just have to modify `bootstrap.less` in the core bootstrap directory after upgrading. [0]: https://www.smashingmagazine.com/2013/03/customizing-bootstrap/ [1]: https://github.com/thomaspark/bootswatch/

The bootswatch project (basically themes for Bootstrap) uses a similar system, though they generally have two less files, one for overriding variables, and a second one for theme-specific additions. https://github.com/thomaspark/bootswatch/tree/gh-pages/swatc...

Cool project! I ended up doing most of it by hand. I started by just playing around with variables.less, but it wasn't giving me the variety I wanted, so I added an extra less file for more custom stuff. You can check them out on the gh-pages branch in GitHub: https://github.com/thomaspark/bootswatch