How to set the background colour of searchbar in OnPlatform using dynamic resource?

<SearchBar x:Name="searchBar"
               Placeholder="Search"
               TextChanged="OnSearchTextChanged"
               TextColor="{DynamicResource NoteTextDark}">
            <SearchBar.BackgroundColor>
                <OnPlatform x:TypeArguments="Color">
                        <On Platform="Android" Value="{DynamicResource NotesEditorColor}" />
                </OnPlatform>      
            </SearchBar.BackgroundColor>

</SearchBar>

Above code throws an invalid cast error on DynamicResource NotesEditorColor

Also, it works for DynamicResource NoteTextDark without any problem

if (DeviceInfo.Platform == DevicePlatform.Android) 
                {
                    searchBar.SetDynamicResource(SearchBar.BackgroundColorProperty, "NotesEditorColor");
                }

Instead of the xaml, writing this in the xaml.cs code behind file worked