Plot Style Monochrome selected, drawing plotting in color

[RockyBrown4134]

I have a drawing, that when I select a monochrome.ctb style in the Plot Style Table, the drwing still plots with layer color.

I opened the layer manager and the VP Plot Style  and Plot style are greyed out, and I can not make a change.

Any suggestions?

AutoCAD 2012, using 2007 .dwg format.

Thanks.

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[RockyBrown4134 · Accepted solution]

I have figured out my problem. The drawing contained a layer, that the color was set off of the true color color tab (Ex. 213,183,251). This layer was the only layer plotting in color when the monochrome CTB was selected. I change the color to a color on the Autocad Color Index (ACI) (Ex. 213). That cured the porblem. I don't know why the True Color acted that way, other than being a "true color".