Capsule Blue Bill and Ben, Harvey, Alfie & Bertie???

Yep, these are based on the episode, "Bill or Ben?" in which one of the twins is painted blue to prevent them from playing tricks on new engines, such as Connor, who don't know there are two of them. Both ended up repainted after the other one tricked Kevin into doing so while Victor was away.
They went back to their original liveries in any future appearances.