What is the difference between the clutch buttons? Brown vs. Grey? Both are just wear items, are the materials different? Does one wear quicker than the other? I snapped off 2 of the new brown ones while changing them yesterday and since the greys had no wear, I installed the new grey ones in their stead. Just wondering if I need to get a new set ordered and tear it back down right away or just keep an eye on them for wear and change them out for the correct ones down the road when necessary.