Here’s a video showing how to Color a Kicad(or, other) STEP part for use in Kicad.
• Example uses a randomly selected Kicad STEP file. I load it in a dummy Footprint that I use for viewing STEPs/WRLs in Kicad.
• Using FreeCAD (Part Workbench).
Note: Though I didn’t click it in the video, I have a custom Toolbar containing the Tool from Part Workbench. Thus, I don’t need to change workbenches…
• Select a Single Face (needed for Enabling the Color Tool), Click the Coloring-Tool Icon, then, select the Faces to color
• Export>‘STEP_with_colors’
FOLLOW_UP - not shown so, just want to mention: Can expand the imported file and select items (as opposed to selecting Faces) and Set/Change the ‘Appearance’ (Right-Click or Menubar). That will change the color of the selected item(s) instead of just the faces.