How much is considered "acceptable"?
Obviously, if it's really blue, dabo dee dabo da, then you have issues
But, say this guy for instance...
Mild, I know. But it was only run for about 2 miles before I pulled the top end to inspect. I was surprised that there was discoloration that quick.
This is on a stock E50 crank with brass bushing, which is not sloppy, and whose oiling hole is still aligned.
Would you be more worried about the crank bushing, or just attribute this to a cheapo quality wrist pin?