Colors should change depending on light/dark color scheme

[MaxDesiatov]

Thanks to the amazing research done by @Cosmo, it can be seen that multiple colors change based on the current color scheme, not just primary/secondary:

[MaxDesiatov]

As Devran mentioned, we should pay attention to the var provider: AnyColorBox property on Color.

[Cosmo]

In my research, for OpenSwiftUI, I found out that the type Color doesn't hold any color values -- only another class type of AnyColorBox.
Its the renderes job to figure out what that value of AnyColorBox represents.

By default, in SwiftUI you have SystemColorType: AnyColorBox and DisplayP3: AnyColorBox.
SystemColorType represents values like .red, .blue, .purple, -- so only names.
And DisplayP3 stores values in RGBA channels.

A color of type DisplayP3 is always the same color -- whereas .red of SystemColorType can be different depending on the environment (for instance color scheme).

This architecutre gives the possiblity to implement HexColor: AnyColorBox if you want to.
Or go even crazier. You could write Nanometer: AnyColorBox and store the color value in nanometers and draw with UV or infrared light -- all without modifying a thing in Color.

You can find my implementation of Color here:
https://github.com/Cosmo/OpenSwiftUI/blob/master/Sources/OpenSwiftUI/Views/Color.swift

A similar thing is going on with the Font type where font sizes are not stored in the Core implementation. Only the renderer knows how big a .title should be and look like. This architecture is a bit more complex, but its the only way to become compatible with Apple's SwiftUI and remove platform specific dependencies to get fully platform-agnostic.

[carson-katri]

Image is also a "late-binding token", I assume for SFSymbols and the imageScale/other image-specific environment values.