I have selected all layers as VP Color: Color 253(grey) inside of the Viewport. In the preview it changes the color but when I plot, it does not. I've tried changing every block to ByBlock.
Preview:
Plot:
I understand that some blocks are true color inside them and this will require a seperate change but most are blocks are on 0 and bylayer inside them. Even 3dSolids aren't changing when I plot.
@melliotmahoney Changing only the Layer colors anywhere means all of your objects (even ones inside blocks) have to be set to color=BYLAYER.
This block content for example has overrides that ignore BYLAYER for color, so they will always be in color (and using a CTB plot style table will not flip them to monochrome either).
So... fix your blocks content first is what would be what needs to be done for the result you want.
