Hi hereward welcome to the forum, I too think you're confusing the Loco and the Dynamometer car. Have a look at this link
http://tinyurl.com/l3fo97p which shows fictional renditions of Deltic DP1 in various colours. I quite like the prototype 'Deltic' decorated in the crimson and gold scheme of the pre-war LMS streamliners, what's your favorite Deltic DP1 colour.