(This issue is reserved for the EuroPython 2023 sprint. If you are not participating in the sprint, please refrain from working on this issue. Thanks!)

The Textual CLI has a command textual colors that displays the variables defined by Textual's design system.
Extend this command/app to show the named colours that Textual recognises, as seen in the Color API documentation.

Take a look at color.py to see how to fetch all named colours that Textual recognises.

To create a separation between the design system variables and the named colours, consider having each in its own tab.
This will also make it easier to extend textual colors if we eventually add other "themes".

Good luck and have fun!