I have the 6-18063 Commodore Vanderbilt. As has been stated here, it is a beautiful, HEAVY engine, but a disappointing puller. I think I would have to call it dark gray - almost black. Specifically to Skip’s question, being one of those weirdos who keeps old paper catalogs, I checked my 1999’s - I have 5: Heritage, Preview, Vol. 1, Vol. 2, AND Vol.3. I did not see the 18063 in any of them. I’ll have to keep looking in case there was a separate flyer (a strong possibility since I also purchased a set of heavyweight cars to go with the engine). Here are a couple of pics of the engine so you can judge the color.
Here is the first Lionel O-27 Commodore Vanderbilt. It was made only in 1936-37. The first O gauge model was produced in 1935.
Here is the whole freight train set with which the Commodore was sold. There was also a passenger train, but I don't have those cars passing through my collection this year. The caboose wasn't made until 1940, but I wanted to show Lionel's affection for NYC. In the 30's, NYC was the only road name on their cabooses other than Lionel Lines.