Answer by Liyun Zhang - MSFT for How to define a MAUI global style for your own class?

You can declare the TextColor as bindable property add then set the style:

public class MyClass : Grid, IDisposable  {      private Label label;      public static readonly BindableProperty TextColorProperty =BindableProperty.Create("TextColor", typeof(Color), typeof(MyClass), Colors.Black);      public Color TextColor      {          get => (Color)GetValue(TextColorProperty);          set { SetValue(TextColorProperty, value); label.TextColor = value; }      }  }

For more information, you can read the official document about Bindable properties