Colin focused on improving the accuracy of developer documentation within the alphagov/govuk-design-system repository, specifically targeting the Type Scale Documentation for the govuk-font SCSS mixin. He identified and corrected a syntax error by adding a missing colon after the $size parameter in the Markdown-based documentation, ensuring that developers referencing the example would implement the mixin correctly. His work was isolated to documentation, with no changes to runtime SCSS code, thereby maintaining system stability while enhancing guidance for future contributors. This targeted fix improved onboarding and reduced the likelihood of support queries, demonstrating attention to detail in documentation and SCSS usage.