Dynamically overwrite Theme

We need to dynamically overwrite the theme for all applications within a platform.  We can add a <style>...</style> on our layout screen to overwrite for regular pages, but we are using LayoutPopup from WebComponents/RichWidgets and the popups aren't applying the style overwrite since we don't have the overwrite on every screen.  I tried using "OnBeingWebRequest" to use "AddStylesheetTag" but this didn't work.  Is there a way to force adding a style to these popups from a single point?  We don't want to update every screen in our environment and eventually we will be using the theme the regular way.


Have you seen this post? It has some good tips...