I missed where you are generating the DXF files in but yes you can. DXF files have a 256 color pallete.
However grabbing nearest color value of textures or grabbing textures at all is a problem for most software that export other then diffuse color.
What you can do is do 2 renders.. one sequence of DXF and one sequence with a normal raster based renderer saving to .bmp format I recall which has the color data you want.
If you place them both in the same folder and then open the first of DXF files in the sequence then ILDSOS will see the bmp sequence and in one of the last options there is something about color.
(Don't know which since I haven't been able to run my ildsos in ages after the license stopped working)
It will grab the color values from the image and applies them to the converted DXF files.