ButtonColorChoices is defined in netbox/netbox/choices.py, not
utilities/choices.py (which only has the generic ChoiceSet base).
Cross-checked every other NetBox-internal import in the plugin against
the actual v4.6.8 source (dcim, netbox, tenancy, utilities packages)
to rule out further path mistakes; all others were already correct.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>