Mazda Repair: Clutch fluid, piston seals, clutch fluid

Question
I have a 86 rx7 no leaks around the slave or master for clutch
The fluid is rusty colored, should I change fluid or is something starting to go
On occasion the pedal does not come up ( not to often)

Answer
Brake/clutch fluid absorbs moisture from the air and so needs to be changed on occasion.  Probably one of the most neglected fluids on a car.

Blackening of fluid is the breaking down of the piston seals inside the master and slave cylinders.

Brownish fluid is most likely a rusting situation of the cast insides of the two parts.  I would imagine it may be time to replace the two as a pair or at the very least rebuild them.  I suggest new ones since rust scoring may destroy a rebuild kit in a short time of use if not removed completely.