Why do HAARP signals change colors/direction ??????????

I've noticed that after awhile the color of the signals at [link to maestro.haarp.alaska.edu] change. At [link to 137.229.36.30] the colors indicate the signal directions. How can they change direction? Or is it a two way signal--outgoing and incoming? Do they bounce? Do they signal that change color (not all do) act as a trigger? Just wondering and looking for answere.