build(deps): bump d3-color from 3.0.1 to 3.1.0 in /demos

Bumps [d3-color](https://github.com/d3/d3-color) from 3.0.1 to 3.1.0.
- [Release notes](https://github.com/d3/d3-color/releases)
- [Commits](d3/d3-color@v3.0.1...v3.1.0)

---
updated-dependencies:
- dependency-name: d3-color
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>