How to set custom property as XAML value?

I have this library with custom Color开发者_JAVA百科 properties. I wanna be able to use these properties in XAML like this:

    <Style TargetType="{x:Type eg:MyWindow}">
        <Setter Property="Background">
            <Setter.Value>
                <SolidColorBrush Color="CustomClass.CustomColorProperty"/>
            </Setter.Value>
        </Setter>
    </Style>

The namespace that contains CustomClass is already referenced. How should I go about this? Thanks.

EDIT:

I just noticed that CustomClass is static, so I can't create an instance of it in XAML. Also, when I type eg:, CustomClass doesn't show up in intellisense. I can't get any of your solutions to work, even though they should, if I had an instance class. Is there a workaround for this situation?

EDIT 2:

This is the actual class and namespace:

namespace Assergs.Windows
{
    public static class OfficeColors
    {
        public class Background
        {
            public static Color OfficeColor1 = (Color)ColorConverter.ConvertFromString("#e4e6e8");
            public static Color OfficeColor2 = (Color)ColorConverter.ConvertFromString("#dce0ed");
            public static Color OfficeColor3 = (Color)ColorConverter.ConvertFromString("#a8c3e0");
        }
    }
}

And this is the XAML namespace:

xmlns:aw="clr-namespace:Assergs.Windows;assembly=Assergs.Windows"

And if I use this line, as suggested by Zenuka:

<SolidColorBrush Color="{x:Static aw:OfficeColors.Background.OfficeColor1}"/>

It throws this error at compile time:

Cannot find the type 'OfficeColors.Background'. Note that type names are case sensitive.

Use this:

<SolidColorBrush Color="{x:Static aw:OfficeColors+Background.OfficeColor1}"/>

Notice the + sign instead of a dot to reference nested classes

I'm asuming you have a Static property on the CustomClass? Then you could use:

<SolidColorBrush Color="{x:Static eg:CustomClass.CustomColorProperty}"/>

but maybe you need to change the namespace prefix...

EDIT:
The problem lies because you're declaring a class in another class... I suggest you move the class Backgroud outside of the OfficeColors class and declare it static or move the Properties of the Background Class to the OfficeColors class (maybe with a Background prefix), OR use namespaces as you are kind of trying.

Have fun :)

EDIT2:
Use Nir's method using the + sign 'aw:OfficeColors+Background.OfficeColor1' to reference nested classes, didn't know that one :)

You would have to declare an instance of the class as one of the resources. (Assuming CustomColorProperty is not static)

<CustomNamespace.CustomClass x:Key=CcInstance />
<Style TargetType="{x:Type eg:MyWindow}">        
     <Setter Property="Background">            
         <Setter.Value>                
              <SolidColorBrush Color="{Binding Source={StaticResource CcInstance}, Path=CustomColorProperty} />            
         </Setter.Value>        
     </Setter>    
</Style>