The attached Python script iterates Rhino layers and sets the print/plot colors of white layers to black.
The idea for the script comes from a user importing an AutoCAD drawing into Rhino. In AutoCAD, color 7 is always an inverted value of the background, working with a dark background means you get that shown as white, using a white background shows this as black, printing on paper (which is white by default) will create black results.
The script ensures what white layers will print as black.
To use the script, just download it (below) and then use the RunPythonScript command to run it.
SetLayerPlotColorsBlack.py (1.8 KB)
Hope this helps someone.
– Dale