Jan Romann developed a JSON syntax highlighting enhancement for the typst/typst repository, focusing on improving the clarity and consistency of data listings. Using Rust, he implemented a theming update that applies distinct colors to JSON object keys and string values, making it easier for developers to distinguish between data elements. He extended the RAW_THEME configuration to support these new color tokens and validated the changes by generating updated reference images for both JSON and YAML themes. Jan concentrated on feature delivery and visual quality, ensuring the enhancement directly supports developer productivity and accurate data representation without addressing bug fixes.