To get the transparent Youtube Player in Mozilla Firefox follow these steps:
1. Open YouTube and press Shift+F2 to open Developer Console in Windows.
2. You will find the console at the bottom of your browser
3.Copy and paste the code given here in console bar:
cookie set VISITOR_INFO1_LIVE Q06SngRDTGA.
4.Restart the browser, you will have a transparent YouTube player installed in your Firefox browser.