I think the Source property is set incorrectly.
<Window.Resources> <ResourceDictionary> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="/WpfControlLibrary1;component/BrushesInAssembly.xaml"/> </ResourceDictionary.MergedDictionaries> </ResourceDictionary> </Window.Resources> <Grid x:Name="LayoutRoot" Background="{DynamicResource RedBrush}"/>
What I did to come to the following:
As an example, I created a new WPF project in Blend and added a management library. I referenced the assembly from the main project.
I added a one-brush resource dictionary, RedBrush.

Than I went to MainWindow.xaml and opened the resource panel. There I linked the dictionary.

After linking, it appears in the list of resources.

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