Where to put "adapter" model object, created by View?

Maybe this is too abstract or vague, but I'm wondering if the pattern is familiar to anyone.


I have a color gradient editor view with a color picker subview that edits the color of the currently selected gradient stop. The design that makes sense to me is to have the gradient editor create a model object for it's color picker, a sort of adapter model that presents the current stop to that picker. (Color pickers take an ObservableObject model that conforms to a certain protocol.) But I can't seem to make this work in SwiftUI. It seems you can only have two kinds of model/state: global objects passed in to the root of the View hierarchy as @ObservedObject or @EnvironmentObject, or simple value types wrapped in @State.