I unchecked Hardware accelleration in VLC Player and now I am able to view Videos without a GREEN screen!
Below is a Google search swiped from a different forum which proved to be the answer and solution.
Apparently MINT 15`s default video drivers for the integrated video on my Haswell i7-4770K are not yet up to snuff?
While the root of the problem is likely hidden in your video drivers, a quick fix is to just disable hardware acceleration in Flash. You might experience a slight decrease in performance, but you'll actually get video working again without going to too much trouble.
In VLC Media Player:
Click on Tools --> Preferences
Click on the Video tab
Uncheck the "Accelerated video output (Ovelay) box.
Save these settings and it should work immediately.
For Youtube videos you could do this:
1) Right click on youtube video.
2) Go to settings.
3) UNCHECK the 'Enable hardware acceleration' tickbox.
4) Refeshed and works fine now.
I also recommend you to install/reinstall your video/display drive