Color Mapping in DXF/DWG and DGN Export

Basic export exports all graphics as a single color. For DGN, this is White, which inverts to black on a white background. For DXF/DWG, it will be either Black or White, depending of the value of the BLACKBG option. It BLACKBG is ON, the graphics will be white, otherwise they will be black.

For Advanced export, colors are mapped on export to DXF/DWG or DGN by their RGB values. Where the DRAW RGB value is close to the RGB value of a defined ACI color, the color is exported as the ACI color; otherwise the RGB value is used. In this context, 'close to' is defined as within a radius of 4 in the RGB space.

DRAW color 10 (White) and color 15 (Black) both convert to ACI 7 (or White for DGN), which will invert if on the same color background. DRAW color 17 (also Black) exports with RGB 0,0,0 and will be black on all backgrounds, while DRAW color 24 (also White) exports as RGB 255,255,255 will show as White on all backgrounds.

Note:
DRAW and AutoCAD color names do not match: DRAW Red has an RGB of 189,0,0 while AutoCAD Red is 255,0,0 (which matches DRAW Brightred at index 18). Similarly, AutoCAD Green has RGB 0,255,0 which does not match the DRAW Green (0,189,0). It does match the DRAW unnamed color at index 20.

Note:
Users can redefine which color is used for indices 1-16; alternative indices are given. AutoCAD only names the first 7 colors.