A few months ago I saw an article from RefactoringUI posted to HN about building your own color palette. https://news.ycombinator.com/item?id=25180180
The concept seemed so simple that I can't believe I hadn't heard of it before as a developer.
It motivated me to create a color picker based on that methodology that lets you build an entire color palette.
It's written in ReactJS + Jest, and the source can be found here: https://github.com/abhchand/niram-color-picker/