Further to the recent query by John Udics and the comments made by Greg Mashiah, there has been a variety of colour schemes used on the railways in Great Britain over the years and many of these can now be seen on both preserved railways and on the main line today.
Back in 1923, all the individual railway companies were grouped together to form the so called 'big four'. These were the Great Western Railway (GWR), the Southern Railway (SR), the London, Midland & Scottish Railway (LMS) and the London & North Eastern Railway (LNER). They all had their own individual colour schemes for their rolling stock
The GWR went for Chocolate and Cream, although I have read that it was originally Chocolate and White; however, the varnish used to go a bit yellowy after time and therefore looked more cream than white. The Severn Valley Railway has a superb collection of ex GWR coaches in original GWR livery :
Clicking on the picture will enlarge it and take you to the others.
The SR chose green :
This is one on the Kent & East Sussex Railway. Again, clicking on the picture will enlarge it and take you to some others.
The LMS coaches were maroon and this is an LMS coach on the Foxfield Railway. As with the others, clicking on the picture will enlarge it :
Finally, the LNER didn't paint their coaches any colour at all. They were built out of teak which was then varnished giving a natural look. The Severn Valley has a super collection of these and here is one of them :
You know what to do to enlarge it and see the others!
In 1948 the railways of Britain were nationalized and the newly formed British Railways chose Carmine and Cream, otherwise known as 'blood and custard'!, as the standard livery for main line coaching stock. All the 'big four' rolling stock was re-painted in this livery and here is one of the ex LNER previously varnished teak coaches in the new colour scheme :
This one is on the Great Central Railway and the picture can be enlarged by clicking on it.
For a few years, BR turned out some more coaches of the 'big four' designs, but, in 1951, they brought out the BR Standard Mark 1 design. These, to begin with, were also painted in the standard carmine and cream livery. There's one at the end of this train on the Llangollen Railway :
Which brings us to 1956 when there were some further livery changes. The carmine and cream was difficult to keep clean so an LMS style maroon livery was used instead. However, it was not universal. The Western Region reverted to a GWR style chocolate and cream livery for its best trains and some Mark 1 coaches were turned out in that livery. See the first three coaches in the above picture.
The Southern Region went back to a SR style green :
The other regions used the standard maroon livery :
However, all this was to change in the late 1960s when the blue and grey livery was introduced :
Hope this clarifies things a bit. Or have I confused you even more?!