No information for TickMajorStyle property in XYDoubleAxis

Hi all,

I am trying to modify the color of the Axis lines in my chart because always appears as "grey" color. I think the name is Tick marks, I mean:

      |-

      |-

 Y   |-

a    |-

x    |-

e    |-

     |_____|_____|_____|_____|_____|_____|_____|_____|

                  X axe

I think is the propertyTickMajorStyle in XYDoubleAxis node but I do not how to set it

<charts:XYChart.YAxes>
<charts:XYDoubleAxis AreLabelsVisible="True" AreMajorTicksVisible="True" AreMinorTicksVisible="False" 
     TickMajorInterval="{Binding GainInterval, Mode=OneWay}" 
     TickMinorInterval="0.1" Minimum="{Binding MinGain, Mode=OneWay}"       
     Maximum="{Binding MaxGain, Mode=OneWay}" x:Name="Gain" Title="Gain (dB)"Focusable="False"
     TickMajorStyle=""/>
</charts:XYChart.YAxes>

 Could you tell me how to change this color? I can not updgrade the ActiproSoftware version.

Thanks a lot,

Eu