Upgrade: Bump color-string from 1.5.3 to 1.5.5 in /ch7/lambda

Bumps [color-string](https://github.com/Qix-/color-string) from 1.5.3 to 1.5.5.
- [Release notes](https://github.com/Qix-/color-string/releases)
- [Changelog](https://github.com/Qix-/color-string/blob/master/CHANGELOG.md)
- [Commits](https://github.com/Qix-/color-string/commits/1.5.5)

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

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

Author: dependabot[bot]