Colour of lines and annotations when exporting to .dwg


We often need to export 2D engineering type drawings, drawn in Rhino, to .dwg for sending to clients. There have been an number of bugs in Rhino 6, that I have been hoping will be sorted out in Rhino 7. I tested them now in Rhino 7 WIP 7.0.20042.9575, 2020/02/11, and some have been fixed but there are now others. I will list these issues under seperate topics to keep responses clear.

  1. When opening a 2D drawing exported from Rhino 6 SR 22, or Rhino 7 WIP, in a .dwg program like Draftsight, NanoCad, or AutoCAD, the colour of all black curves, or layers with colour black, get exported with the colour value (0,0,0). It would be great if they can be exported with the .dwg supported colour (black/white), so that when opened in AutoCAD with a black model space background, the curves are visible:

We have to manually open .dwg drawings exported from Rhino, in AutoCAD (or equivalent), and change all layers with colour black (0,0,0), to colour (black/white), before sending on to our clients.

Can Rhino export this (black/white) colour code to .dwg files?

Hello - see if exporting by Autocad color index does what you need: