Hi HomerJ,
The change you are looking for is accomplished by adding the following parameter to the Site Admin site Configuration tab, if it is not already there, and then set the value you are wanting (note that higher values will result in more system resource usage):
PROJECT_SELECTION_MAX_PROJECTS
Description Maximum number of projects that ALM allows you to include in a graph. Default is 6.
Default value 6
Min value 1
Max value 9223372036854775807
Introduced in release QC 10.00
Introduced in patch GA
System false
As you can see the default limitation is 6. If the Parameter is not listed in the parameter list within the site configuration tab within site admin then you will need to add that parameter and your desired value within the above min and max ranges.
Since the guides do not state whether this value is dynamic or static if you add the value and it doesn't affect the report generation then you may need to restart the ALM services to get the new value to take affect (the guides do not specify which can be dynamically changed and which require a restart to take affect).
There is also a post here detailing the same information: https://eyeontesting.com/questions/6019/how-can-i-add-more-than-6-projects-to-graphs-in-al.html
Hope this helps,
Dan