Apps and shell themes diverge deliberately: what each listens to

The two bits

Why two, not one

• Users have settings-consistent subpreferences with visual hierarchy logic: dark shell + light document apps; light shell + dark code editors. Two bits exist because the design team concluded the same; it's a deliberate combo.
• Complain about the Settings UI instead of the registry: Settings → Personalization → Colors → Custom exposes both toggles independently already. The registry is for automation, not for surviving without an option.
• Older Win32 apps take whatever they hard-coded; they were never subscribed. Your theme flip doesn't respone-break paint their pixels.

Live-testing diagnostics: read the values before concluding the tool wrote them — PowerShell diff both befores/afters — and waypoint-app them against the pivot-key primer. Every per-user flip should be a measurement with un-do, not a narrative.

ProofTune ProjectEngineering notes — every claim here names the bytes a real tool touches. Verify first, install second.