This issue is to discuss and streamline the behavior of design tools in terms of the visibility of the UI controls for users.

This topic is growing complex, so I want us to agree on a terminology:

• contexts: each block that can have styles/settings assigned. Note that some blocks (core/heading) expose many contexts (core/heading/h1, ..., core/heading/h6) and there's also the "global" context that doesn't match any block.
• block UI: the block sidebar available in all editors.
• global UI: the global styles sidebar available in the site editor.

Use cases

Some examples of what we want theme authors to be able to do:

• Disable custom gradients in all contexts, so they aren't visible in the block and global UIs.
• Enable color presets in every context, and make them visible in the block and global UIs.
• Enable font family and its presets only for the global context (this context is only visible in the global UI).
• Enable line height for all contexts, but make it visible only visible in the global UI.

Some examples that we aim to streamline for users:

• User is able to modify the values of the colors (theme presets) for all contexts at once.
• User is able to modify the values of the font size (theme presets) for the paragraph context.

Coda

A related use case but that merits its own discussion is extensibility by 3rd parties. Things like disabling the typography panel entirely and provide their own, or provide a different mechanism to set font families.