Default colour system audit and design update

[trallard]

📌 Summary

It would be good to ensure that the default light and dark themes are accessible, for example:

• have enough colour contrast between colour pairs/groups
• colours/shades are distinct enough
• colours and their use are consistent

🔖 Tasks to complete

• Audit current colours and identify any a11y issues
• Update the themes to fix encountered issues:
  • Preliminary: Add discussed color system to Bokeh code base bokeh/bokeh#14482
  • All in-scope suggestions

🔍 Acceptance Criteria

• There is a Figma file for the default themes, including current and proposed palettes and basic documentation
• Core design updates have been implemented

References

https://docs.bokeh.org/en/latest/docs/user_guide/styling/themes.html

[trallard]

Proposal for base colour palette is almost completed on our end so @smeragoel will be sharing with the Bokeh team as a discussion

[smeragoel]

Proposal is shared with the Bokeh team in this discussion post.

[trallard]

@gabalafou is working now on updating the colours