Today Eastman Kodak Company is the only company we know that tests their color films in this way and makes available the results. Some tidbits from this testing. Maximum graininess for silver negatives occurs between a density of 0.3-0.6 density. Since graininess is perceptual, it decreases with a density increase because of the difficulty in dicerning differences at low light levels. Color films have a higher density at which graininess is most apparent, about 0.9-1.0 density.
Color dyes scatter less light.
Black and white prints exhibit peak graininess at about .65 density, and color prints at about .93 density. These issues can be factored in when shooting and printing. There are density points that increase or decrease the perception of grain. Steer clear of these points in the final print if you want the perception of less grain or maximize them by giving them the density of maximum graininess. Granularity is the king of objective grain measurements.