Now that was an active choice you made. As we understand time, it was the only choice you could have made. But there are likely parallel planes of existence where everything we know is the same, except you would have chosen the green one instead. From there, the timeline would branch off into a different collection of lived experiences. A color choice is fairly innocuous, but apply it in terms of battles, where you'd dodged left instead of right. A choice creates a point of divergence.

Now... these all exist in a parallel space and aren't intended to cross over, but Wonderland exists as a nexus perpendicular to these planes. [He drapes a string of wiring across all three pads.] As it collects us, it could take a version of you from the blue universe, while previous versions of you have visited here from the green or yellow ones.