No worry. Hard plastic black or brown bits are chain tensioner material. Crème or brown colored rubbery bits are left over sealant. A small amount of either is normal.
If you see this, then you need to worry (a lot);
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor