refactor: use Cookies to store color instead of localStorage

[ToBinio]

🔗 Linked issue

❓ Type of change

• [ ] 📖 Documentation (updates to the documentation, readme, or JSdoc annotations)
• [ ] 🐞 Bug fix (a non-breaking change that fixes an issue)
• [X] 👌 Enhancement (improving an existing functionality like performance)
• [ ] ✨ New feature (a non-breaking change that adds functionality)
• [ ] 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• [ ] ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

This PR changes the way the color choice is stored from localStorage to Cookies. This is so that SSR also knows the color choice of the user. Currently, SSR always sends the default color so you get kinda flash banged if you have a different setting.

I know that the workaround with the Cookie expiration date isn't the cleanest. But I believe it would be worth it for the improved UX. If you disagree or have a better idea of how to fix the problem let me know.

📝 Checklist

• [ ] I have linked an issue or discussion.
• [ ] I have updated the documentation accordingly.

[pi0]

Hi. Thanks for your time on this PR but undocs is meant to output static files so this change doesn't pretty much works with this current design.