Hi David - @clement posted a file that is nearly that, some time ago - I’ve tweaked it to color each object differently.
RandomObjectColorEach_ClementG.py (605 Bytes)
The original is here -A script to assign a random colour for selected items? [Keyshot export] - #11 by clement
To use the Python script use RunPythonScript, or a macro:
_-RunPythonScript "Full path to py file inside double-quotes"
-Pascal