Please could you add a new css class to any jobs which are currently in the build queue, particularly in the aggregator view?
This will help to check if a build is really currently green, or may be waiting for resources to build a new change.

The wall display plugin has this behaviour, with CSS showing yellow dots on the dashboard when items are queued. (the number of dots representing the position in the queue). Example images can be seen in: https://wiki.jenkins-ci.org/pages/viewpage.action?pageId=57184000