I would be very nice if I had a column with a kind of traffic lights indicator in "View Issues"

The thresholds should be configurable with the number of days since the issue was opened/assigned.

For example, if issue was opened/assigned since 10 days ago but less than 20, the issue "indicator" change from green to yellow.
If issue was opened/assigned since 20 days ago, the issue "indicator" change from yellow to red.

This can easily permit to distinguise "new", "medium-aged" and "old" issues.