Green zoom button?

I am trying Scrivener for the first time and have come to a problem in the tutorial. I encountered this sentence:

You may find this text a little scrunched up now. If so, click on the green “zoomâ€

The green zoom button is a feature of all OS X windows. You can find it in the top left-hand corner of the window, one of the three “traffic light buttons”. They may all be grey if you have the Graphite Theme set, though.
Best,
Keith

That did the trick! I did have the graphite display mode, and now that it is the blue mode, I have traffic lights. Thanks much!