You can define the default workspace visuals for the whole account in Account manager. You can use the default visuals in any workspace. (Note that you need to have the default visuals in place)
Using the Default Workspace Visuals
You can import the organization's default visuals into any workspace by navigating to Workspace Manager > Visuals, clicking 'Import visuals,' selecting 'Import visuals from default visuals workspace,' and finally choosing 'Import visuals.' Your workspace will now use the organization's default visuals.
Setting the Default Workspace Visuals
The default workspace visuals can be set in the Main User Dashboard. From the "Workspaces" tab, you can search the workspace that has the visuals you want and set them as the default from the three-dot menu.