In the Styles table, you have all available styles, including the ones defined in other projects that have been shared with yours in the multi-project configuration. As an example, the current style selected in the sample is defined in project GW_ResourceWeb, a global web project. The name of the project that contains the resource definition can be obtained from the Current CSS file path field, in the Properties > Style tab. In the example, the path points to:
GW_ResourceWeb: WebContent/css/customer/dijit/main.css
The path is automatically set when the style is selected.