Export to STEP with different colors

I have this specific problem right now: Step Export with colored face

I would like to export as STEP, with subfaces in different colors. The supplier we send the step files to, really need colors on some geo to convey information like materials, front-back etc. I can only make it work by exploding the geo, and then exporting. However our supplier wants the geo unexploded.

  • Is it still not possible to export color information on a per face basis?
  • Can I somehow attach some meta data to a face without exploding the geo?

Thanks!

Could a solution be to include a new “Display Color” on materials?
Then in the Display Color on the object there would be a 4th option of “From Material”.