The Open Pixel Art project is a collaborative art project that aims to teach people how to contribute to open-source projects while collaborating on an art project. The project is based on simple principles, such as every user being able to contribute exactly one pixel with a color of their choice, and pixels can be layered. To contribute to the project, users need to create a pull request where they add their pixel to the `data/pixels.json` file. Once validated by bots, the pull request is automatically merged, and the changes are deployed on Netlify. The project also includes a special TwilioQuest mission that guides users through the process of contributing to the project from scratch. The mission teaches various concepts related to open-source projects, including Git and GitHub, and awards experience points as the user progresses.