Theme changes are applied globally across all users

[awaisahmed119]

Bug Description:

Currently, when one user switches the theme in Theia, the change is applied globally. As a result, any other user accessing the same instance will also see the updated theme.

This behavior is problematic in a multi-user environment, where theme preferences should ideally be user-specific (or even browser-session specific), rather than shared globally. Do we have any settings to achieve this?

Expected behavior:
We want theme should be scoped per user or per browser session, so that one user’s changes do not affect others.

Steps to Reproduce:

1. Go to settings(bottom left icon) -> Themes -> Color Themes
2. Apply any different theme
3. Theme will be applied globally.

• Operating System: Any
• Theia Version: 1.64

[msujew]

Hey @awaisahmed119,

I've converted this into a discussion, since this is working as intended. Theia is not designed to be used in a multi-tenancy use case and does not offer any support for it. See #13022 for more info on this.

In theory, there are ways to support your request, for example by sourcing user preferences from a webservice or similar instead of the file system. However, there are many inherent security and privacy concerns involved with hosting one Theia instance for multiple users - I wouldn't recommend using the approach at all. See the linked discussion above for how to securely set up multi-tenancy for Theia apps.