You may or may not have contamination in the fluid. Mercon has an additive that can be mistaken for small carbon particles. If you take a new container of Mercon and pour a small stream with light behind it, you can see a dusky particle throughout it.
It also is not uncommon to have very dark contaminated fluid from the rack mixed with your new fluid. Many 95's had fluid that got especially dark from very slight aluminum wear in the rack case. It may be advisable to flush the system.
Inspect the fluid, but do it after you have a hard look at new fluid from a new bottle.
