Williams Southern E7s: Same models - why different colors?

Could be the factory paint color was different on each run of the engines in question.

If both engines were from the same run, then somebody re-painted it. On Williams the only way to tell if an engine is from the same run is to look at the circuit board numbers, and the details on the circuit board.

What the manufacturer means by a run is the same time frame for something, per say, was it made in May of 2000 or was it made in May of 2003? Each would be a different run according to the way companies do things, so a detail such as a hood being painted a different shade will not surprise me.

Lee Fritz

On the second set, what appears to be white is the imitation aluminum which on the prototype actually had a Dupont paint number in the gray family. 

I wouldn't worry about the difference in shade if the engine is otherwise okay.

They were delivered from EMD that way.

I wasn't able to locate a picture of an E7, but here's one of an F3:

And one of an E6:

(Both images from Kalmbach Classic Trains Magazine Specials)

Rusty

Rusty - thanks for that pic! 

Dewey  - not worried at all - I kinda LIKE that I have the two colors

RARE collector item!!!! I have a set of Weaver E-8 in the white....both look good!