When the original 47/7s came south from Scotland in 1990, 47703/04/06/12/17 initially went to Parcels, of which 47703/12/17 got the red/grey livery in the first half of 1991. July 1991 saw these five loaned to NSE for use on the Waterloo-Exeter route. 47704 had a generator failure soon after and was sent back to what had by then become RES, it was put through Doncaster and emerged in RES colours that December. The other four stayed with NSE until the 159s arrived in 1993 and then transferred to RES but were never repainted.
As for the later batch of 47/7s, as Chris suggests, the majority of these had already been repainted in RES colours as 47/4s before modification and renumbering. Some were repainted at the same time as they were renumbered, particularly those dragged off various scrap lines to expand the fleet. Apart from the Royal pair, the only second batch 47/7 to operate in a non RES livery was 47783, which stayed in Intercity Swallow for a short time after renumbering from 47809.