Makes the key headers standout

[skrawcz]

It's hard to quickly scroll and see the headlines. Went with a conservative black, rather than green or something.

Changes

• data view headers should now stand out

Before:

After:

How I tested this

• locally

Notes

Checklist

• [x] PR has an informative and human-readable title (this will be pulled into the release notes)
• [x] Changes are limited to a single goal (no scope creep)
• [x] Code passed the pre-commit check & code is left cleaner/nicer than when first encountered.
• [ ] Any change in functionality is tested
• [x] New functions are documented (with a description, list of inputs, and expected output)
• [x] Placeholder code is flagged / future TODOs are captured in comments
• [x] Project documentation has been updated if adding/changing functionality.