Custom fields at Project Level

Anyone know if it is possible to add custom fields at the project level?

For example I would like to add an overall status field (Green - Amber - Red) on the project level instead of the issue level. 

Subsequently I would like to use that field in listview / a status report / dashboard.

Is this possible and if so can someone point me to a short tutorial how to achieve this?

thanks in advance.

Mike.