M.O.W. Gray?

I don't think I've seen a set color called MOW gray.  A lot of MOW equipment gets painted a "primer" like color (yellow is alo popular) but not all roads us the same shade, some are more like offwhite and some a more like battleship gray.

The Weaver cars look to me to be a proper shade of gray for MOW equipment, although I think in real life it would weather out to a lighter shade pretty quickly, especially on older wooden cars. Some RRs like the Milwaukee Road used Boxcar Red on their MOW equipment, which weathered out to various faded shades of maroon like you'd see on their older diesels. I only mention weathering because it gives you flexibility in your color shades when you're painting/repainting stuff.  

The PRR's MOW equipment were gray until the early 50s, then they were painted yellow.  Since my layout era is late 40s, I've been wanting to paint my few MOW cars gray but haven't got around to it yet.

Ron

Each railroad painted their MOW equipment differently, there was no standard.  The CB&Q and CGW used orange.

Rusty

Here is a former CGW caboose, now MOW, on the UP Northwest Line at Arlington Park, IL. It is gray (although, you might not know it, as I took this photo yesterday through the dirty, tinted window of a METRA coach).

As Jerry notes, most Milwaukee Road MOW equipment was painted boxcar red. There were some exceptions. Many cranes were painted yellow, as well as snow plows, flangers, and old F7B units used as power cars for electric rotary plows. MOW tank cars were black. Ice cars were light blue (the blue K-Line Milwaukee Road reefer is copied after a non-revenue ice car used to deliver ice to MOW crews). According to Nighswonger (Milwaukee Road Color Guide to Freight and Passenger Equipment) the Milwaukee started painting outfit cars gray after about 1960. The Weaver ribside car is undoubtedly taken from a photo in that book (see below). The number is the same. The sliding door on the prototype was removed and replaced with a normal-sized "people" door. When I get mine, I might try to make that modification on the model. The Milwaukee Road also used gray for wooden boxcars transporting hides, to make sure that once they were used for that purpose, they were never used for anything else. As Nighswonger points out, the paint job was probably unnecessary, as the smell would instantly identify a hide car anyway. 

Much better, Southwest Hiawatha....thanks!  I may get over that way today, and if its still there, I'll try to get a better photo.