I'm sure I'm not the only developer who is sometimes faced with the task of both deciding on and implementing the theme colors used by my apps.
Since I'm more of a developer than a designer, I think Mike Rydstrom has done some great work here by publishing this rather extensive utility designed to help someone choose and refine the color themes used by an app -- including both light and dark modes.
I also really appreciate that Mike's documentation for this tool is extensive. In fact, it's hard to imagine a case where this tool wouldn't come in handy, especially at the beginning of a project when you're trying to get your theme colors decided upon and the associated code off the ground.
Speaking of flex_color_scheme (see previous article), in this video, Majid Hajian sits down with Mike Rydstrom and walks through a pair-programming exercise demonstrating how to implement this functionality with an example application.
This is a very nice tutorial if you'd like a more hands-on demonstration of this significant package.