Joesph Chamberlain (1139) has kindly edited the original Intercity textures for the PMDG BAe JS4100 Jetstream 41 so that they now depict every registration (originally I only depicted G-ICJE), the updated textures are available now from the Downloads page.

G-ICJA through to G-ICJU have been painted, although you don't need to install them all. However, you must always install the texture.Intercity folder.