The colour was chosen as it made a change from green and the car shown to the public at Earls Court in 1959 was actually painted Pale Primrose. The reflection running down the side of the car is particularly pleasing, showing that all the "panels" are in line. The registration plate is not a road registered number as far as know, but the code given to the car during development. DP standing for Development Project.
The blog itself seems to be proving popular. We have been mentioned on the Twitter pages of Electric Dreams over in the States and also by Danni O'Laisips Brake Hard blog. Thanks guys.