<SolidColorBrush x:Key="{x:Static telerik:VisualStudio2019ResourceKey.AccentBrush}" />

<Window x:Class="ChangePaletteSettingsPerControl.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
        xmlns:local="clr-namespace:ChangePaletteSettingsPerControl"
        local:MaterialThemeExtensions.PrimaryNormalColor="Red" 
        local:MaterialThemeExtensions.PrimaryHoverColor="SteelBlue" 
        local:MaterialThemeExtensions.PrimaryFocusColor="Green"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">

    public class MaterialThemeExtensions
    {
        public static Color GetPrimaryNormalColor(DependencyObject obj)
        {
            return (Color)obj.GetValue(PrimaryNormalColorProperty);
        }

        public static void SetPrimaryNormalColor(DependencyObject obj, Color value)
        {
            obj.SetValue(PrimaryNormalColorProperty, value);
        }

        public static readonly DependencyProperty PrimaryNormalColorProperty =
            DependencyProperty.RegisterAttached("PrimaryNormalColor", typeof(Color), typeof(MaterialThemeExtensions), new PropertyMetadata(OnPrimaryNormalColorPropertyChanged));

        private static void OnPrimaryNormalColorPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            MaterialPalette.Palette.PrimaryNormalColor = (Color)e.NewValue;
        }

        // ...