(Just in case it's not obvious: Click the yellow link to see the animated visualization.)

Each debris has a different color. What does it mean?

Do the page download all the initial data and make a simulation or it download the positions periodically?

There is a ring at high altitude. What is it's origin? Geocentric satellites? (I think there is another ring at medium altitude, but I'm not sure.)

Does this show the satellites that are currently in use or only the unuseful debris? Can you add a button to show/hide them?