Slave cylinder reservoir sludge

Hey guys, I was riding my '08 SD the other day, and I noticed that there is a small amount of dark junk in the bottom of the slave cylinder reservoir... It still works fine, but is that a byproduct of the seals going? If not, where is that stuff coming from and what is it? The bike has 10,700 miles on it.
Thanks!

This is not related to the sludge inquiry but recently at 18k kms mileage, my slave leaked. the OEM slave uses only one o-ring on the piston. I simply opened up the slave, cleaned the assembly and installed a new viton o-ring. It's a simple fix in case your seal blows.

Sorry, i forgot, you must be reffering to the Reservoir mounted on the handlebars and connected to the clutch radial master. On the ducatis, this is often a problem after just 5k kms mileage ( a darkening of the fluid ). I suspect it to be the pistons on the radial cylinders to be rubbing against the walls. I just normally drain the fluid and re-flush with new. Otherwise, opening up the master and cleaning would be more thorough.The KTM though, uses mineral oil or an SAE7.5w fork oil against the DOT4 fluid of the ducati. So the seals/pistons may not be interchangeable.