Changing the Foreground Color of an Indeterminate ProgressBar
You would think that the following XAML changes the indeterminate progress bar’s foreground color:
<ProgressBar IsIndeterminate="True" Foreground="Aquamarine" />
Unfortunately, that doesn’t work. You will need to override the following value in the default theme resource dictionary:
<ResourceDictionary.ThemeDictionaries>
<ResourceDictionary x:Key="Default">
<x:String x:Key="ProgressBarIndeterminateForegroundThemeBrush">Aquamarine</x:String>
</ResourceDictionary>
</ResourceDictionary.ThemeDictionaries>
You can add that override to App.xaml, or to a new resource dictionary that’s merged into App.xaml:
<Application
x:Class="Sample.App"
xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml">
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Common/StandardStyles.xaml" />
<ResourceDictionary Source="Common/CustomStyles.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
CustomStyles.xaml:
<ResourceDictionary
xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml">
<!-- Global Overrides -->
<ResourceDictionary.ThemeDictionaries>
<ResourceDictionary x:Key="Default">
<x:String x:Key="ProgressBarIndeterminateForegroundThemeBrush">Aquamarine</x:String>
</ResourceDictionary>
</ResourceDictionary.ThemeDictionaries>
</ResourceDictionary>