A few days ago I published a new release of the ANTLR4 extension for Visual Studio Code, which contains a number of fixes and new features. The light color theme is now complete as well and you get railroad diagrams for your grammar rules and even entire files. These can be saved to disk (as HTML with embedded svg), so that you can use them in other documents. Code lens support was added as well, which allows to (optionally) show rule reference counts. Hope you enjoy the new release.