Hello Syam,
Just browse to SMW01 and highlight the BDoc in question and click on the Errors/receivers tag.
See the list of recievers. It might very well be the case ECC gets the data but another site like XIF_IDOC or Groupware doesn't.
So unless all the receivers get the data, BDoc state would stay YELLOW.
You may also check transaction SMOEAC to know if the subscribers(SITES) to a particular replication object have been maintained properly or not. You might remove them as well depending on your business need.
Regards,
Rohit