Color of lower unit gear oil

[aquadj]

I have twin 1998 Yamaha 250hp ox66 EFI motors. Today I drained the gear oil from both lower units and 2 completely different color oils came out. The starboard was yellow - green and slightly creamy similiar to the new Yamaha gear oil. The port (counter rotating ?) was black. The main bearing went on the port motor and I had a new power head replaced in August. Could that have anything to do with it?

[slim]

its normal for the counter-rotation motor gear oil to become black alot sooner then normal rotation motors.