GWR loco colours 1900–1947
(rgb 1,46,3; hex: #012E03)
(rgb 1,54,2; hex: #013602)
chrome orange lining
(rgb 255,128,64; hex: #ff8040)
(rgb 101,45,44; hex: #652d2c)
(this is based on the BC381c series)
(rgb 146, 38, 2; hex: #922602)
The loco body colour adopted by Swindon from 1881 was based on a 'middle chrome green' pigment. It replaced various earlier shades of green, including the darker 'holly green'. Wolverhampton however continued to use a dark blue green shade until at least 1894.
Whilst the basic colour pigment remained the same, what varied was the number of coats of varnish applied. Since the varnish imparted a brown tinge, the application of many coats of varnish in early years made the resulting finish look darker than in later days, when the number of varnish coats was reduced. Hence, for modelling purposes, a distinction is made between various 'eras' of painting practice. Bob Shephard explains this in more detail below.
The colour panels for the greens given here are based on J.N.Slinn's 'Great Western Way', HMRS 1978. Colour values in rgb and hex are given, but should be regarded only as a guide.
Commercial paints favoured by some modelmakers are Precision Paints GWR Green for the pre-1928 shade, and BS.224 Deep Bronze Green and Halfords Rover Brooklands Green for the post-1928 shade. It is always wise to check though, particularly with commercial spray cans, that the colour of the contents of the can match what is given on the cap.
Bob Shephard, owner and paint chemist of Precision Paints until 2004, writes in 2018:
"From my past researches, most railways were fairly particular about their loco and coach colours but not about wagon and building colours. The main problem with colour matching in pre-WWII days was that all pigments were natural, and varied in shade. This made colour matching very time consuming, and accurate colour matching extremely difficult. The other problem was that locos and coaches all had varnish coats over the colour coat, because gloss finish paints were non-existent until synthetics came along. And because the varnishes were all natural, they were a dark brown shade so this effected the appearance of the paint coat. Locos also had 3 or 4 coats and it is the varnish in paint that discolours with heat. Thus loco paint was a different, darker, shade after about a week after application! You will see on the Phoenix catalogue that there are 4 different shades of GWR Loco Green listed. Actually there was only 1 shade between 1881 and 1945, and one shade prior to this, on the 1875 livery panel. (The 1875 shade was discontinued by Phoenix though).
When I colour matched them I had the original GWR livery panels from Swindon Works, to work with: 1875, 1881, 1906, 1928 and 1945 dated full livery panels, complete with lining. Where the varnish coats had chipped off, the actual colour of the Loco Green was the same from 1881 right up to the 1945 panel. The 1875 Loco Green was different to all the other panels – it was quite a bit darker, and a bit browner too. On the backs of all the panels were instructions for the number of coats of paint and varnish to be applied. As the panels got newer, so the number of varnish coats reduced from 5 coats on the 1875 panel to none on the 1945 panel. During WWII, the way of making synthetic paints, varnishes and pigments was discovered, and the last GWR panel – 1945 (must have been produced late in the year, after the war ended) was full gloss synthetic paint and was not varnished. This showed the true colour of GWR Locomotive Green, and it matched, exactly, all the other panels, from 1881, where the varnish coats had been chipped off.
As another 'aside', many refer to GWR Locomotive Green as Middle Chrome Green. This is not actually correct. Middle Chrome Green was the pigment colour used to make the GWR Locomotive Green, which is what it was called on the backs of all the panels."