[SoCA]

Besides the coloring(black/purple) and labeling...what is the difference between the Hayes hydro systems. I personally have the "purple" version.

I just found out that the lever mounting is a little different between the blacks and purples (I was going to get a set of Razor Rocks but my LBS didn't have the "purple" style in stock).

 

[RideDS]

Hayes "Purple Hayes" differ from other brakes in that they are abusive-riding specific, so they are slightly larger and stronger. They are different than the HMX, which are mechanicaly controled, while the other versions are full hydraulics. Aside from larger rotors and more strength, your discs are very similar to standard Hayes Hydraulics.