ruby.sidebar.AllGreen

 All Green All green refers to the state of the executing Example; it means all Examples are executing and passing. This terminology derives from unit testing in Smalltalk and then popularized by JUnit. In Smalltalk, their process was:
 * Red: Create a failing test
 * Green: Get the failing test to pass
 * Blue: Refactor

This is essentially what this tutorial advocates. JUnit turned this into red-bar, green-bar. When the GUI of JUnit executes, it has a progress bar that indicates either:
 * Red: one more more tests have failed
 * Green: all tests executed so far have passed