StTest/MyTests/Pages/MainPage.xaml

<Page x:Class="MyTests.Pages.MainPage"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
      xmlns:local="clr-namespace:MyTests.Pages"
      mc:Ignorable="d" 
      d:DesignHeight="425" d:DesignWidth="800">
    <Grid Background="{StaticResource color1}">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="124"/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>

        <StackPanel Background="{StaticResource color2}" 
                    Grid.Column="0">
            <Button Name="CreateTest"
                    Height="30"
                    Margin="5"
                    Content="Создать тест"
                    Click="CreateTestClick"
                    Visibility="Collapsed">
            </Button>
            <Button Height="30"
                    Margin="5"
                    Content="Тесты"
                    Click="TestsCatalogClick">
            </Button>
            <Button Height="30"
                    Margin="5"
                    Content="Профиль"
                    Click="ProfileClick">
            </Button>
        </StackPanel>
        <Frame Name="MainContentFrame" 
                   Grid.Column="1"
                   NavigationUIVisibility="Hidden">
        </Frame>
    </Grid>
</Page>