You can create a new paint with one of these 3 constructors:

It is generally suggested to never create a paint object, or any other object in onDraw() as it can lead to performance issues. (Android Studio will probably warn you) Instead, make it global and initialize it in your class constructor like so:

public class CustomView extends View {
    
    private Paint paint;
    
    public CustomView(Context context) {
        super(context);
        paint = new Paint();
        //...
    }
    
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        paint.setColor(0xFF000000);
        // ...
    }
}