+For any given channel, you can see that it is active in the live or preview
+by looking at its border. If it's got a red border, as in the leftmost
+input, it's live (either on its own, or as part of the side-by-side view).
+Similarly, if it's got a green border, as in the second input (you can
+see it if you look closely; it's a somewhat lighter shade of green),
+it will be marked with green. On conflict, red (live) wins, since it is
+the most important piece of information.
+
+If you have many channels, the default single-row view can make for previews
+that are somewhat small. If so, you can switch to the *video grid display*;
+see :ref:`audio-views` for more information.
+
+