- [ ] Start this issue's title with `Docs:` or `Docs feedback:`. ## Problem to solve User documentation on syntax highlighting in GitLab is confusing and contradictory. If I understand correctly, syntax highlighting applies to the following: - Viewing files in a repository (in the GitLab UI). - Editing a file in the Web Editor. - Editing a file in the Web IDE. - Viewing a snippet. - Editing a snippet. The [syntax highlighting documentation](https://docs.gitlab.com/ee/user/project/repository/files/highlighting.html) states the following: > GitLab provides syntax highlighting on all files through Highlight.js and the Rouge Ruby gem. It attempts to guess what language to use based on the file extension, which most of the time is sufficient. > > The Web IDE and Snippets use Monaco Editor for text editing, which internally uses the Monarch library for syntax highlighting. From my testing in GitLab is that the syntax highlighting theme selected in the user profile applies to all the above UI elements **except for the Web IDE**. There are some noticeable differences between the appearance of these elements and I don't understand why. **Objectives:** - Confirm which UI elements uses the syntax highlighting theme selected in the user profile. - Update the user documentation. ## Further details With syntax theme "Solarized Dark" selected in my profile, the following UI elements look as follows. **Viewing a JavaScript snippet** {width=60%} **Editing a JavaScript snippet** {width=60%} **Viewing a JavaScript file in a repository** {width=60%} **Editing the (same) JavaScript file in the Web Editor** {width=60%} <!-- * Any concepts, procedures, reference info we could add to make it easier to successfully use GitLab? * Include use cases, benefits, and/or goals for this work. * If adding content: What audience is it intended for? (What roles and scenarios?) For ideas, see personas at https://handbook.gitlab.com/handbook/product/personas/ or the persona labels at https://gitlab.com/groups/gitlab-org/-/labels?subscribed=&search=persona%3A --> ## Proposal <!-- Further specifics for how can we solve the problem. --> ## Who can address the issue <!-- What if any special expertise is required to resolve this issue? --> ## Other links/references This issue was discovered while working on https://gitlab.com/gitlab-org/gitlab/-/merge_requests/179316+.