Zigfu + Unity 3d how to make certain joints red if cross limit

Hi,

I recently installed Zigfu unity3d package. I am playing with zigfu. I could get 3d Avatar from Unity 3d working on browser using Zigfu.

In the app 3d Avatar imitates user. Now I want that while imitating users motion I also want that some joints should be shown as red if user moves his joints out of limit given by me.

for ex. user arms x axis limits is 50. so if user arm moves above this limit then it should be indicated as red on browser kinect window.

Please give me some pointer how can I do that or at least a hint to proceede.

Thanks, Govind