I have searched the forum and can't seem to find an answer on a couple questions I have.

1st:  What is the difference between the Brake Collars in red and gray?

2nd:  When adjusting the brake collars do I need to adjust them in pairs or can I adjust them individually?

Just moved to the Citica 201D from a BPS Rick Clunn BC and all I can say is once you go Shimano you will never go back. ;D

Thanks,

1st.- The only difference that I have seen in the red and grey is the thickness wich means more contact and better breaking.

2nd.- I don't use them in increments of 2 and I have shimanos that are 12 years old and has never needed any repair.

Shimano FAQ

The lighter colored collars are light, the darker are heavier.

I have read some place that when adjusting the collars you should keep them balanced.  If 2 on make them 2 opposite, if 3 on put every other one on, etc.

In the link Burley posted, it also said that you can use any number of weights in any configuration, so i would assume that it doesnt matter if you adjust them in pairs.