Have you seen Iain Rice’s article on converting the Bachmann 2-8-0 to represent a CV prototype? It appeared in the November 1999 MR, and it included several prototype photos. One shows Engine 471 with white-striped running boards, but that seems to be unusual. All the other engines shown lack the stripes, and when Marty McGuirk painted the model (Iain built it for him) he didn’t stripe the running boards.
While I’m not an expert on CV I do have a lot of info on CN steam and find that both CV and GTW tended to follow the lead of their parent. In that regard most CN steam had white striped running boards except switchers. I have photos of consolidations and most had the white stripes. I even have a photo of one with white painted tyres on the drivers and leading truck. All CN passenger steam had white running boards and tyres. Most freight had white running boards.
Of course there is the exception to every rule. This is the only one I have ever seen painted this way but I do have other photos of CN/GTW 0-8-0s with running boards painted white.