I'm looking into how to programmatically control color filters in the Accessibility settings under "System Settings" -> "Accessibility" -> "Color Filters"--in particular the "Intensity" and "Filter type" settings.
As far as I have gathered, changing this setting can only be accomplished using the CoreGraphics APIs or Accessibility APIs (I've poked around GitHub, Stack Overflow, and queried some LLMs), but there doesn't seem to be a clear cut example for doing this using public facing APIs, without ripping off source code from another project wholesale or using private APIs.
My goal is to overlay a color filter at either a per-application or system level to help with accessibility. If there's a way to overlay this capability on an application-by-application basis as a third-party developer, that would be the most ideal scenario. For example, modifying the look and feel/UX for Launchpad, Photos, etc, as a third-party developer without accessing the source code of the application that I'm modifying the look/feel for (with appropriate user consent of course).