Gene,
Color is such a subjective thing. We all don't see the same color the same way. My suggestion would be a Testors Wood, which is a light tan, weathered with a wash of ink/alcohol. A Boxcar Red would be "reddish brown" once weathered, but most of these water tanks were natural wood or actually paintd in the home railroad colors. Check out your own supply or the LHS for a color you like. Since this is a plastic kit, I would stick with the spray enamels. Once you have the color the way you want it, hit it with Dullcote to knock down the shine of the enamel.
Sorry this is not a definite answer, but you have to like the color yourself.
B-) & :x
