They are probably close enough in colour. You may find the Hornby ones ride a bit high on their bogies , but overall not a problem. Just in case you don't know, though, (and apologies if you do)I'm not sure the RMB is strictly accurate in Crimson/cream. You will see them like that on preserved railways , but I think they were delivered in Maroon on BR.
Others with greater knowledge of this will be able to comment.
Russell
Others with greater knowledge of this will be able to comment.
Russell