ComboBox styling in WPF - wpf

Question

I have a problem with a ComboBox. I wanted to change its apparency by overriding its style, but I have some problems of appearance, and I can't find where are they.
My ComboBox has this appearance:
I have two problems:
I don't know where to change the foreground of the expandable menu... Wherever I change it, it remains white!!
When I choose an option, the Text of the ComboBox appears twice, one in dark blue and one in white, as you can appreciate on the image. And I don't know how to change it...
My style looks like this:
<!-- All ComboBox styles -->
<ControlTemplate x:Key="ComboBoxToggleButton" TargetType="ToggleButton">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition Width="20" />
</Grid.ColumnDefinitions>
<Border
x:Name="Border"
Grid.ColumnSpan="2"
CornerRadius="5"
Background="{StaticResource DarkGradient}"
BorderBrush="{StaticResource SolidBorderBrush}"
BorderThickness="1" />
<Border
Grid.Column="0"
CornerRadius="5,0,0,5"
Margin="1"
Background="{StaticResource TextBoxBrush}"
BorderBrush="{StaticResource SolidBorderBrush}"
BorderThickness="0,0,1,0" />
<Path
x:Name="Arrow"
Grid.Column="1"
Fill="{StaticResource TextBoxBrush}"
HorizontalAlignment="Center"
VerticalAlignment="Center"
Data="M 0 0 L 4 4 L 8 0 Z"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter TargetName="Border" Property="Background" Value="LightGray" />
<Setter TargetName="Border" Property="BorderBrush" Value="Gray" />
<Setter Property="Foreground" Value="DarkGray"/>
<Setter TargetName="Arrow" Property="Fill" Value="DarkGray" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
<!-- ComboBox TextBox -->
<ControlTemplate x:Key="ComboBoxTextBox" TargetType="TextBox">
<Border x:Name="PART_ContentHost" Focusable="False" Background="{TemplateBinding Background}" />
</ControlTemplate>
<!-- ComboBox style -->
<Style x:Key="{x:Type ComboBox}" TargetType="ComboBox">
<Setter Property="SnapsToDevicePixels" Value="true"/>
<Setter Property="OverridesDefaultStyle" Value="true"/>
<Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
<Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
<Setter Property="ScrollViewer.CanContentScroll" Value="true"/>
<Setter Property="MinWidth" Value="120"/>
<Setter Property="MinHeight" Value="20"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ComboBox">
<Grid>
<ToggleButton
Name="ToggleButton"
Template="{StaticResource ComboBoxToggleButton}"
Grid.Column="2"
Focusable="false"
IsChecked="{Binding Path=IsDropDownOpen,Mode=TwoWay,RelativeSource={RelativeSource TemplatedParent}}"
ClickMode="Press">
</ToggleButton>
<ContentPresenter
Name="ContentSite"
IsHitTestVisible="False"
Content="{TemplateBinding SelectionBoxItem}"
ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}"
ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}"
Margin="3,3,23,3"
VerticalAlignment="Center"
HorizontalAlignment="Left" />
<TextBox x:Name="PART_EditableTextBox"
Style="{x:Null}"
Template="{StaticResource ComboBoxTextBox}"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Text="{TemplateBinding Text}"
Margin="3,3,23,3"
Focusable="True"
Background="Transparent"
Visibility="Visible"
Foreground="DarkBlue"
IsReadOnly="{TemplateBinding IsReadOnly}"/>
<Popup
Name="Popup"
Placement="Bottom"
IsOpen="{TemplateBinding IsDropDownOpen}"
AllowsTransparency="True"
Focusable="False"
PopupAnimation="Slide">
<Grid
Name="DropDown"
SnapsToDevicePixels="True"
MinWidth="{TemplateBinding ActualWidth}"
MaxHeight="{TemplateBinding MaxDropDownHeight}">
<Border
x:Name="DropDownBorder"
Background="{StaticResource TextBoxBrush}"
BorderThickness="1"
BorderBrush="{StaticResource SolidBorderBrush}"/>
<ScrollViewer Margin="4,6,4,6" SnapsToDevicePixels="True">
<StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
</ScrollViewer>
</Grid>
</Popup>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="HasItems" Value="false">
<Setter TargetName="DropDownBorder" Property="MinHeight" Value="95"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="LightGray"/>
</Trigger>
<Trigger Property="IsGrouping" Value="true">
<Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
</Trigger>
<Trigger SourceName="Popup" Property="Popup.AllowsTransparency" Value="true">
<Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0,0,4,4"/>
<Setter TargetName="DropDownBorder" Property="Margin" Value="0"/>
</Trigger>
<Trigger Property="IsEditable"
Value="true">
<Setter Property="IsTabStop" Value="false"/>
<Setter TargetName="PART_EditableTextBox" Property="Visibility" Value="Visible"/>
<Setter TargetName="ContentSite" Property="Visibility" Value="Hidden"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
</Style.Triggers>
</Style>
If anyone can help to solve this, will be really appreciated!
EDIT:
I could solve the problem of writing twice the value by changing this:
Text="{TemplateBinding SelectionBoxItem}"
And then adding to the ItemSource selection sentence, and then setting it by default, but I still have the problem of being not able to change the Foreground of the combo...
EDIT2:
I discovered one thing: when I create the list, I do this:
listPrecissions = new List<Precisions>()
Where Precisions is a class that I created with two strings. If I create it with a direct string:
listPrecissions = new List<string>()
and add the items, it has a black foreground. But have no idea why...

Answer 1

Your question lacks the following styles TextBoxBrush, SolidBorderBrush and DarkGradient.
I don't know where to change the foreground of the expandable menu... Wherever I change it, it remains white!!
Setting the Foreground property on the ComboBox seems to change it for me (with your styles applied).
When I choose an option, the Text of the ComboBox appears twice, one in dark blue and one in white, as you can appreciate on the image. And I don't know how to change it...
<ContentPresenter Name="ContentSite" and <TextBox x:Name="PART_EditableTextBox" are responsible for displaying the current item for two different cases. First is the normal one, the second is when the ComboBox is marked as editable (IsEditable="True"). In your style the default for PART_EditableTextBox is Visible, so just set it to Hidden.
<TextBox x:Name="PART_EditableTextBox"
Style="{x:Null}"
Template="{StaticResource ComboBoxTextBox}"
HorizontalAlignment="Left"
VerticalAlignment="Center"
Text="{TemplateBinding Text}"
Margin="3,3,23,3"
Focusable="True"
Background="Transparent"
Visibility="Hidden"
Foreground="DarkBlue"
IsReadOnly="{TemplateBinding IsReadOnly}"/>