May I prevail upon any GWR experts out there please? I have a treasured family photo showing my grandfather (a GWR driver) and his cousin (fireman) standing with their dock shunter at Birkenhead. The loco is an Armstrong 0-6-0 saddle tank number 1979 of the 1901 class built in 1890-91. Above the warehouses in the background are the funnels of steamships and masts of sailing ships. My father thought it would be Vittoria dock. The dock opened in 1909 and I guess the photo dates from around that time. The sepia print is becoming faded so I am having it digitally restored and ‘colourised’ by a professional. My questions concern the colour of the loco. Would a dock shunter of that era been painted in GWR green? Was there only one shade of green prior to nationalisation? Any help or pointers will be much appreciated.