Bridgekeepers robes are distinguished by colour from regular ones... it is just an extra pimped-up combat armor that can look really cool. If somebody is that keen of getting a pimped-up combat armor, I say let them have it for a small additional price. CA is very hard to get anyhow, why not wear it in style?
And if someone of GM team wants to distinguish himself from crowd, there is always power armor.
This is more of a style theme and does not change economical balance of game in any way. Besides, if you set for example a limited amount of wear or repair for it it is not going to be there for ever and people would think twice before pimping their sturdy CA into stylish and uber cool, but less lasting and same protection providing, robes. It makes sence to me, how about you?
Think about it please.