I think the idea with an alert is that the fact that the alert is triggered and pops up is more 'in your face' than any color scheme.
If it pops up everytime you run the report it will likely lose its efficacy and people will just ignore it.
You can use the trigger formula so it only pops up under specific conditions and you can dynamically set the text of the alert (say to the name to the person that need to contact) using the formula field for the text.
This also can be done as dynamic forumla placed in a report header that is conditionally displayed that might be easier to read or gives more specific information that would not fit in an alert.
I have set some reports to hide all the data except for a prompt indicating that the content is void for x reason and follow steps 1,2,3 to correct the issue.