If the colours are not one-hundred-per-cent correct, they are very close to it, certainly as I remember them (at least the ones that were still painted that way when I rode the B&O). When the C-C first issued these in the late 1960s (these are N scale cars), the color scheme was more like that Blue and Grey that you may have seen on other models. I do not remember any B&O passenger cars painted like the initial scheme offered on the C-C cars
Arnold still offers the RR HWs painted in the colour scheme of which you may be thinking. I do not remember any B&O passenger cars painted in that colour scheme.
C-C offers the HWs in the same colour scheme as the photograph in the link.
I do remember B&O cars in that colour scheme.
Kato also offered smooth side B&O cars in the same scheme as the photograph in the link. Those cars are not in current production in B&O, but again, you might find some at shows or in a LHS as NOS.
If you want the B&O smooth sides in the older C-C colour scheme, you will have to hit the train shows.
As for what pulled them, I am assuming that you are interested in N scale, as the photograph is of an N scale car. For the B&O, it would mostly be passenger cab diesels.
C-C, LL and Kato offered E-8s. LL offered two different kinds, a plastic frame and split-metal frame. The plastic frame came in A units only. The other two, as well as the LL metal-frame, had B units available. The only one in refcent production is the LL metal frame, but the others are not dificult to find at shows.
LL offered E-7s and E-6s in B&O. The E-6s came in an A-B set, the E-7s are A units only (the B&O had no E-7Bs). They are plastic frame and not in current production, but are not difficult to find at shows.
The Kato offered passenger F-3s in B&O.
Atlas offered torpedo boat GP-9s in N scale, in ‘as delivered’ colours. While these locomotives eventually did pull smoothsides on the B&O, o