Bhor Ghat section - ये ना ही है जन्नत, ना ही इधर है कोई पर्वत, यह जगह है हर एक Railfan का जो सबकी पूरी करे मन्नत - Sahil Khandare

I took the YPR - Puri Garib Rath last Sat and at BZA took my kids along to watch the Loco change.
I was surprised to see the Loco being changed was WDG - 3A and questioned one of the engineers participating in the Loco change about the Loco being used for a Passenger train.
[As there was lots of noise, its possible I misheard and misunderstood the following conversation, experts pls correct]
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explained that this Loco has both Speed Pipe [White Colour] and Brake Pipe [ Green colour] and hence can be used to pull passenger coaches. A Goods only Loco will have only the Brake Pipe.
Is it really the case? Also the 2nd Loco was a WAM - 4 [I think] and I noticed FP and BP painted over the pipes. FP for Speed Pipe?