I would like to follow up with further information on behalf of Greg:

Here's what I would suggest would be the most flexible, and which I think would preserve existing behavior:

Control
            Theme (Property Group)
                        ThemeClassName
                        ThemeName
                        CascadeToChildren (new property for Forms and other containers.)
Default = False for Form control (to preserve existing behavior)
Default = True for other containers
                        UseParentTheme (new property for all controls, except Form)
Default = True
                        UseGlobalTheme (new property for Forms only, if you can implement this feature using an application setting.)

For new users, like me, I would set CascadeToChildren = True for each Form, and that would cause all child controls to follow form-level theme changes, unless I set a control’s UseParentTheme = False.

For existing users who like the current behavior, they would use the controls normally, and form-level theme changes would not propagate. A minor breaking-change is that non-form container theme changes would propagate to the container's controls. But I think that is probably expected.

Regards,

Greg

 

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik