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I would like to see a red-light stimulus that is gradually raised in intensity from a very low level (say mag.24-25) which checks first where the stimulus is first seen (a test of dark adaptation and rod sensitivity) to the point where color is first perceived. Then, the identical test with a green light. If the cited studies are valid, the faint green light would first be seen as red and then turn greenish at some light intensity.

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1) The red appears only in context where there are high and medium ligths (the medium lights are reddish). If the stimulus was presented alone it was "grue".
2) I do not exactly know which data from Shaefrer you refer. But if they are those in the paper on limitin magntide as a function of magnification, the large variance is due to the large difference of factors (the data are grouped per diameter and magnfication but include a large interval of environmental conditions). We tested under the same sky same place, same instrument and same magnification and a dozen people have 0.2-0.4 magnitude spread.

Apart from the two points above, the idea of making tests with monochromatic light is interesting. I would like to write to the authors... The test should be carried out alternating lights of different colors (from low lights upwards) in a casual order, say gren red and blue and asking the test person to push one of three buttons to record the perceived color (more or less as the test done in audimetry). I am making a homemade test with a red led flashlight and the SQM. A pure monochromatic light seems easier to detect. So far it seems to me that the numbers I get are in reasonable agreement with the literature (a little better for the monochromatic light but I will tell you).

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