This is dirty suspension oil that I removed from this fork before
permanent damage occurred to internal components.
Here I am adding fresh oil to front suspension fork
ADVICE
To increase the service interval, wipe the stanchions off after every ride.  
Try to wipe dirt away from seal, and not force it down into seal. Most
manufacturers recommend service every 50 hours of use. This could be
longer in dry conditions, or less in muddy conditions.
dirty oil
stanchion
seal
new oil