Overriding PhoneAccentColor doesn't work

I just want to customize the PhoneAccentColor within my application, but it doesn't seem to work.

I made App Resources looking lik开发者_JAVA技巧e:

<Application.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="Utils/Converters.xaml"/>
            <ResourceDictionary Source="Resources/Styles.xaml"/>
        </ResourceDictionary.MergedDictionaries>
        <ViewModels:ViewModelLocator x:Key="ViewModelLocator" d:IsDataSource="True" />
        <Resources:ResourcesWrapper x:Key="ResWrapper" d:IsDataSource="True" />
    </ResourceDictionary>
</Application.Resources>

And in the Styles.xaml I redefined the PhoneAccentColor like this:

<Color x:Key="PhoneAccentColor">#FFFF0000</Color>

But for any reason the default phone accent color is still used. For example I'm using the PerformanceProgressBar from the toolkit which still uses the default color instead of the definied red.

Is there anything I missed?

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Solved: Seems like you also have to override within the Styles.xaml.