Note: AutoCAD is able to access a plot style file if it is in the same folder as the drawing which uses it.
AUTOCAD PLOT STYLE MISSING MAC
or you can permanently turn on access to the Library folder using the Terminal application, which is the Mac equivalent of the CMD prompt for Windows. Are you a recent arrival from R14 I ask because we might as well.
CONVERTPSTYLES command is what you use to reset the DWG file to the plot style type you desire to use. This choice is saved in the DWG file, not your system or anyone else' system.
AUTOCAD PLOT STYLE MISSING FOR MAC
When you receive a drawing that was last saved in AutoCAD and you want to plot it in AutoCAD LT for Mac running in macOS, you will find that you can't locate the Plot Styles folder to add the acad.ctb color dependent plot style table.