There was no standard colour used by the factory, unfortunately. Rationing meant that they had to use whatever they could get their hands on at the time, but the shades of green did conform roughly to standard colours.
Up to the end of 1945(ish) they used Mid-Brunswick Green, then Dark Brunswick Green up to about 1951 when they changed to Apple Green (the closest I have found to this is Amazone Green). Wheels were always red on the tractor, nearest colour was Massey Ferguson Super Red, but varied on the implements; on your riding carriage green or red wheels would be acceptable, I have seen them painted in both colours from the factory.
I hope that helps.
.
