Hi there,
I am pretty sure that it's because you are not only running NWBC 4.0, but your NWBC theme has been set to corbu.
Your personas 2.0 connection is using SAP default, so it comes up blue. If you wanted to see it the same as you render via NWBC, then add "&theme=corbu" to your personas connection string (minus the " marks).
If you want to make it a permanent change, it needs to be set on the service. Talk to your friendly BASIS person, since it will be a setting on the service. Have fun!
Cheers
Di