It would be great to add macOS support to the [`systemPreferences.getColor` method](https://github.com/electron/electron/blob/master/docs/api/system-preferences.md#systempreferencesgetcolorcolor-windows) to allow electron apps to fetch the [system colors](https://developer.apple.com/design/human-interface-guidelines/macos/visual-design/color#system-colors) and [dynamic system colors](https://developer.apple.com/design/human-interface-guidelines/macos/visual-design/color#dynamic-system-colors). This would be a pretty big deal for apps that are trying to fit in with the OS, especially since the colors change depending on several factors and Apple strongly discourages hardcoding them:

>**Don't hard code system color values in your app.** The color values provided below are intended for reference during your app design process. The actual color values will fluctuate from release to release, based on a variety of environmental variables. Always use the API to apply system colors.

>**Don't try to replicate dynamic system colors.** Dynamic system colors—some of which may be patterns—fluctuate from release to release, based on a variety of environmental variables. Instead of trying to create custom colors that match the dynamic system colors, use the dynamic system colors.

I am very unfamiliar with how most of this stuff works, but based on the docs I linked it seems like this could be a relatively simple interface to NSColor...?
atom/browser/api/atom_api_system_preferences.cc
v8::Isolate* isolate,
    v8::Local<v8::FunctionTemplate> prototype) {
  prototype->SetClassName(mate::StringToV8(isolate, "SystemPreferences"));
  mate::ObjectTemplateBuilder(isolate, prototype->PrototypeTemplate())
#if defined(OS_WIN) || defined(OS_MACOSX)
      .SetMethod("getAccentColor", &SystemPreferences::GetAccentColor)
#endif
#if defined(OS_WIN)
      .SetMethod("isAeroGlassEnabled", &SystemPreferences::IsAeroGlassEnabled)
      .SetMethod("getColor", &SystemPreferences::GetColor)
#elif defined(OS_MACOSX)
      .SetMethod("postNotification", &SystemPreferences::PostNotification)
      .SetMethod("subscribeNotification",
                 &SystemPreferences::SubscribeNotification)
      .SetMethod("unsubscribeNotification",
                 &SystemPreferences::UnsubscribeNotification)
      .SetMethod("postLocalNotification",
                 &SystemPreferences::PostLocalNotification)
      .SetMethod("subscribeLocalNotification",
                 &SystemPreferences::SubscribeLocalNotification)
      .SetMethod("unsubscribeLocalNotification",
                 &SystemPreferences::UnsubscribeLocalNotification)
      .SetMethod("postWorkspaceNotification",
                 &SystemPreferences::PostWorkspaceNotification)
      .SetMethod("subscribeWorkspaceNotification",
                 &SystemPreferences::SubscribeWorkspaceNotification)
      .SetMethod("unsubscribeWorkspaceNotification",