'02 250 sx tranny

This is my first used bike in some time,I have ridden it twice.Ran great,shifted through the gears no problem.When I ride,I use the clutch for upshifting and a 50/50 mix when downshifting.I have used Maxima 80 mtl.Before I rode it for the first time,I changed the tranny fluid.When it first drained,it seemed fairly greyish.Probably more than I noticed in other bikes and there was a collection of metal around the plug.I rode it and changed it again yesterday...seemed to be more metal in the drain pan than there should be,plus the oil was quite grey again.I only rode it for 20-25 laps.
My question is,what is a normal amount of metal in the tranny fluid? Am I just getting worked up over nothing? Thanks.