Ok, so I got some more info.

The whole thing is a little complex.

The original STEP AP203 "edition 1" did not define colors at all. AP214 added color support. Then after that AP203 "edition 2" also added in colors to AP203.

MoI will write an AP203 file with colors in it, but some programs may only expect to see AP203 "edition 1" files, and may only try to read color info from AP214 files. This seems to vary quite a bit between programs.

In the future it should be possible to make MoI have an option for writing AP214 type files, but it's something that is currently under development in the I/O library that MoI uses, so that won't happen until MoI v4 probably.


So anyway the summary is: MoI does write color info currently to STEP files, but due to some of the history of the STEP file format some programs may not read it in from the particular type of file that MoI currently writes.


- Michael