Kirks post highlight the versatility of using a color head. Another thing one can do is to make a 'grid of exposure factors' for each single color setting. One can then use calculated exposure factors, instead of adding red neutral density.
So, on the grid you would have Max YELLOW to Max MAGENTA on the X axis and the same on the Y axis.
Each block in the grid would have the number of stops difference between the two step wedges in the grid. ie 60y to 60m might have an exposure difference of 1.5 stops. Then your exposure factor for that change would be:
FACTOR = 2^(stops differnence)
So, in that box on the grid you would put a factor of 2.8, and so on...