Bug reports, pull requests, and compliments are welcome on GitHub at https://github.com/bbugh/vscode-change-color-format. If you find it useful, let me know on Twitter! I love hearing from people who use my work.
To run, just clone the repo and then run yarn. You can debug the extension in Visual Studio. To run tests, follow the Testing Extensions instructions on the VS Code site.
If you're new to open source contribution, this Beginner's Guide to Contributing to Open Source Projects is a great resource.