DoubleCAD does support AutoCAD Style Based Tables (STB) but not Color Based Tables (CTB). You can import AutoCAD STB tables in DoubleCAD using the File/Print Style Manager/ Import AutoCAD Print Style (down arrow next to the New button).
Most AutoCAD users use .CTBs for plotting so we're looking at supporting CTB's in DoubleCAD as well.
.CTB's are not embedded in the AutoCAD drawing so the .CTB must also be packaged and sent with your drawing.
As far as colors changing during round-tripping with DoubleCAD and AutoCAD, that should not happen and maybe a bug. Do you have a drawing or steps to reproduce so we can try that?
OK, I understand the ability to import an stb, I have done it a couple of times, but does ACAD Know what to do with a drawing setup with a DCAD pstyle and is there a way to export a DCAD pstyle to stb?
Packaging the ctb is not a big deal (etransmit), but DCAD doing something with it would be great even if it just converted it (and the drawing) to a DCAD pstyle (or even an stb that could be imported). In ACAD a drawing must be one or the other, it cannot be both.
As far as color change: the physical color does not change, but the color name changes from say Index
color 10 (red) to a true color value of 255,0,0 so the ACAD ctb no longer recognizes it as an Index
color and instead treats it as a true color. I'll come up with an example and post it later.