When starting a new Run of a matrix job you can open the "Job page" (http://jenkins:8080/job/AMatrixJob/)
On this page there is an icon for each sub-job of this MatrixJob.

The icon for a given subjob is:
-> Sucess/Failed if the sub-job has finished
-> Blinking icon if the sub-job currently running
----> Sucess/Failed if the sub-job has not started yet (Previous sub-job status retrieved from last build)

It would be helpful to have a grey icon for sub-jobs that have not been started yet in the current build.
Instead of the previous sub-job status.

Especially if you need to check sub-job results as you may think a sub-job has failed whereas it has not been started.