https://autocadtips.wordpress.com/2011/12/07/plot-color-regardless-of-ctb-or-stb-file/
Correction. This tip does not override .stb files – sorry for any confusion.
This tip can either be the answer to a problem or a helpful tip that can be applied to a drawing. I stumbled upon this while creating PDFs from a drawing. There was a stubborn layer that wouldn’t plot as Black or a shade of grey even though I specified it to plot using the “Monochrome” .ctb file.
Anytime you specify a color to an entire layer, individual object(s) or a viewport override, you have the option of using 3 color categories. One of which is called “True Color.” (This is similar to specifying material colors in 3Ds MAX)
Properties override by either the Properties panel on the ribbon or the Properties Palette
A True Color viewport override is applied in the Layers Properties Palette when a viewport is activated.
These “True Colors” don’t seem to play by the rules when plotting. Regardless of the .ctb file that you specify, they will plot their True Color. So if you have some of these True Colors set, you may want to find an equivalent on another tab or hopefully you will be plotting on a black & white plotter.
In the pictures shown below, I show that one layer called “Logo” has its color set as a “True Color.” I did this so that the logo will stand out when I plot.
I then start the Plot dialog (ctrl +P) and after specifying the plotter and page size I set the .ctb file to be “Monochrome.” Notice that in the layout tab, the walls and windows are a red-ish color
The result (in this case, a PDF) shows that the logo is the only object that printed in color thanks to this “True Color” setting.
~Greg
AutoCAD Tips 
Greg,
This seems helpful as I can follow how to fix this problem. Except that I cant seem to find the “override” command where you specified, only the “remove override…” There doesn’t seem to be a toggle for both “Override” and “Remove Override”. Can you help?
Hello, I’m having trouble printing my lineweights. I have the” details.ctb” in plot table and “plot with plot styles” checked however its all the same lineweight when I print. HELP. Thanks again.
I needed to plot something in color just for review. It was much quicker to plot to a PDF with my color table set to “None”. Then I printed my color PDF in color. I just had to remember to change anything in yellow to a darker color (I chose 34 brown).