In InDesign you simply listen for an AppReskinEvent (see the documentation) which passes an AppSkinInfo object you can interrogate for necessary values. The eaiset thing to do is to simply bind your UI elements to the colors and chrome passed in the object. I'd be surprised if the same thing isn't true of PhotoShop.
Thanks for the reply Bob! I was able to add a listener for the AppReskinEvent and was able to change the skin of my extension if the user changed the Interface settings. So far, so good.
Note that, when the extension is launched for the first time, it has its default skin irrespective of the skin/theme of the application. How can I get the applied skin/theme of the application so as to set the skin/theme of my extension as well. Because, it all comes down to triggering the AppReskinEvent. If its not fired, then my extension's skin/theme won't change.
Awaiting a response.
All you need to do is during application initialization (before creationComplete, if you are binding UI variables to skin states and want to set up that way), just grab the HostEnvironment (CSInterface.instance.hostEnvironment). The environment has an appSkinInfo member which you can use to initialize the app. Hope this helps!
I was able to do the needful!