(18 Jul 2017, 5:27 pm)Jimmi wrote N21 uses B5's.
Judging by the VOSA registration, from September 3rd the N21 will be extended to Durham, South Road College's whilst the N20 is registered as withdrawn from the same date.
There's a photo of the B9 on Facebook and the base coat is in the same style as the Angel, mostly black with either orange or red (difficult to tell) going along the bottom.
It is Angel style orange. Which perhaps hints at a 56 brand revision in Angel/Castle Express style, with Angels also very much needing a repaint. The 56s have faded quite badly when you see them next to the Citylink Versa of the same age.