Try a search for "Scale Effect". You may get some results with that.
Although frankly, I've rarely seen anyone try and make a color match at a show, display or otherwise commented on the great job of scale effect on a particular model. Painting is a subjective issue and as long as its close and looked at within the context of its presentation then it works. A quick perusal of the armor section at a contest will show you a variety of shades of dunkelgelb, olive drab, russian green, nato black etc. amongst the models entered. Some dark, some light, some with various tones and hues to further muddy the waters and make for an interesting view of the history of afv's. The day that someone shows up with a 1943 Panzer IV at 1:1 scale and pars it outside (sans 60 years of weathering, oxidation, and or repaint) and the judges whip out a color spectrometer to make a comparative analysis of a model and the vehicle and take into account scale effect, emmited light source, atmospherics and reflectivity, then it'll be time to worry about scale effect.
Same goes with figures. As long as within the context they are viewed is correct, the colors are subjective and things like wear, weathering, dye lots etc all make enough of a variance that scale effect is moot.
Mike
"Imagination is the dye that colors our lives"
Marcus Aurellius
A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!"