I think that option is more for display and would show you the pnl of each selection if you were to press the 'Close all positions' button i.e. how much that selection would have added to your overall greened profit.
Don't think there is an option to do what you're asking but would be good if there were an option to green/red based on the individual runners bets rather than overall book.
Level profit based on individual selection
With this option ticked the Level Profit column will display two amounts.
The larger font amount is based on your overall Profit & Loss whereas the smaller font amount displayed below it is only based on the individual selection's P&L.
http://www.gruss-software.co.uk/Betting ... e/help.htm