In my notes I have 14 A class in green with waist line (including A46 in dark green), and 24 in plain green.
For the C class, 8 green with waist line, and 12 in plain green.
So the plain green was a bit more common, but not by much.
There may have been a few more which I haven't found photos of in the relevant era.
Some locos in each class never carried green, going straight from silver to black or black and tan.
The more significant missing livery from the IRM A class models was black with roundel and small numbers at the base of the sides. Fortunately, not too hard to produce from the A55 model in the early plan black scheme.