Need Help with color randomization

Hey.

Im very new to Blender, and hit a bump while creating a low poly tree.
The thing is im trying to randomize the color of my leaf material so that it has a range of 2 colors when rendered.
All the tutorials on this i found where outdated and the node editor behaved differently at the time as it is now, so can someone please explain to me how to do so now in 2.78 because im stuck very badly :P, would be greatly appreciated.

Cheers!

Use the random output of the Object Info node and a color ramp for the colours you want to pick from


yeah i did not notice that i have to create the material in the node editor not take an existing one, solved the problem, thanks mate!