Powershell Graphs

Hi,

I'm trying to change the color of the values at the moment it does a yellow and blue and i would like red for disk used and green for disk free, but wondering what command i would need to input.

here is the code i have used some code i found on the internet in the meantime.

Function Create-PieChart() {
       param([string]$FileName)
       [void][Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
       [void][Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms.DataVisualization")
       #Create our chart object 
       $Chart = New-object System.Windows.Forms.DataVisualization.Charting.Chart 
       $Chart.Width = 400
       $Chart.Height = 320 
       $Chart.Left = 10
       $Chart.Top = 10

       #Create a chartarea to draw on and add this to the chart 
       $ChartArea = New-Object System.Windows.Forms.DataVisualization.Charting.ChartArea
       $Chart.ChartAreas.Add($ChartArea) 
       [void]$Chart.Series.Add("Data") 

       #Add a datapoint for each value specified in the arguments (args) 
    foreach ($value in $args[0]) {
              Write-Host "Now processing chart value: " + $value
              $datapoint = new-object System.Windows.Forms.DataVisualization.Charting.DataPoint(0, $value)
           $datapoint.AxisLabel = "Value" + "(" + $value + " GB)"
           $Chart.Series["Data"].Points.Add($datapoint)
       }

       $Chart.Series["Data"].ChartType = [System.Windows.Forms.DataVisualization.Charting.SeriesChartType]::Pie
       $Chart.Series["Data"]["PieLabelStyle"] = "Outside" 
       $Chart.Series["Data"]["PieLineColor"] = "Black" 
       $Chart.Series["Data"]["PieDrawingStyle"] = "Concave" 
       $Chart.Series["Data"]
       ($Chart.Series["Data"].Points.FindMaxByValue())["Exploded"] = $true

       #Set the title of the Chart to the current date and time 
       $Title = new-object System.Windows.Forms.DataVisualization.Charting.Title 
       $Chart.Titles.Add($Title) 
       $Chart.Titles[0].Text = "Disk Usage Chart (Used/Free)"

       #Save the chart to a file
       $Chart.SaveImage($FileName + ".png","png")
}

# Disk Space Fucntions

$Disks = @(gwmi Win32_LogicalDisk -Filter "DriveType=3")

foreach($disk in $Disks)

{

$UsedDisk = [System.Math]::Round(($disk.Size - $disk.freespace)/1gb)
$FreeDisk = [System.Math]::Round($disk.freespace/1gb)
}

# Where the graph is going to get saved too

Create-PieChart -FileName ((Get-Location).Path + "\chart-$computer") $FreeDisk, $UsedDisk
$ListOfAttachments += "chart-$computer.png"