Game color is in common miniature gaming shades farther there tends to be a middle tone a highlight and a shade for each tone.  Model color is for realistic painting, each tone is a match for a full scale paint for historic subjects,  Usually it is not adjusted for scale effect of highlight.  Aircolor is the same as model and railroad color just pre thinned and strained for airbrushing, it is also so posed to have finner ground paint pigments of higher quality to give better results when airbrushing.