Plugin didn't work.
There is an example of plugin that exist in qt examples it is called 'styleplugin' this simple plugin must change color of button to red but when i run it. it wont change the color of button. (If you want test whole project go to example tab of qt creator and type 'plugin' then choose style plugin example)
Any details you could provide? Version? Compilation probs? Did the plugin compile? It works amazingly well here.
By the way, the button doesn't do anything. It should appear red when you start the application.