Try M-Color It gives you cymk color and bitmap capability. It assigns by layer though so you may have to change the way in which you assign your layers. It is a little tough to get used to but it is a great tool once you get aquanted with it's functions.
You can use "M-Color" or you can play with the CTB file.
Copy and rename an existing CTB (acad.ctb) and edit that. You won't be able to edit the colors on screen but the output can be modified.
Double click on the CTB file.
Click on the "Table View" tab
(left hand side) Click under color (3 down) "use object color"
A pull down should appear with the ability to change the color.
SKROLL ALLLL THE WAY DOWN TO "True Color"
Now play with the "RGB" values
[red/ green/ blue]
You can produced "pantone" or any other color you want ... on a color plotter.
