wpf - Cannot access property bound to DataGridTextColumn in another element such as Foreground -

i have simple datagrid itemsource bound

observablecollection<issue>

issue class object containing various properties. have handful of datagridtextcolumn items bound properties of issue object , works expected.

binding="{binding path=duedate, stringformat=dd-mmm-yyyy}" header="due date" 

now, want set color of foreground depending upon if date has passed expect can this:

foreground="{binding path=duedate, converter={staticresource datehaspastcolorconverter}}"  

where

datehaspastcolorconverter 

returns 1 of 2 colors depending upon if date being past has past.

my problem can access issue.duedate property in main column binding not available foreground or other property. properties available actual view model itself.

how access properties of row to , why not available? it's binding member recognises issue properties , other bdinginds recognise view models properties.