My suggested movement method:
Explanation of what occurs: At first nobody has a color. The bosses determine which color you get. They cap at 6 people with a color. They give their colors by priority of threat to those attacking them. When people are dead, this can change with bosses trying to make an equal number of people each color. Thus getting rez's fast is important.
When starting, move to the areas marked in mauve. Be spread in that area. Everyone will get their colors. If you somehow get the wrong color, stand against the wall while everyone moves (blue path,) then take the central path (marked in lime.) Dps and kill adds as needed.
The bosses will go to blow up, but you are already safe. Ignore the mechanic. Instead, move along the red path (from blue-> mauve.) This puts you back at the starting point, where you should be dpsing the boss on your side to get that color.
Tanks continue their dance of trading bosses. People run over to bash when needed. Otherwise these positions.
The dancing was really killing us, and I think this is a fairly solid explanation of what fixes that problem. It doesn't need to be quite this strict, but this shows how the flow should go. Consider it the basic steps which will keep you from being blown up, or from blowing up, other people.
Finally, when going to rez, do not forget about colors. I saw a number of people kill those rezzing when a rez was nearly done. They would run up, blow up the person trying to rez of the other color, and thus cause the rez to fail. Now, instead of two dead people in a spot, there are three.