Page Metrics is based on the script javascript
justice.js, it allows captured and displays top-level measures, it will give you an overview of the performance of your web pages.
You can set your own budget. The results are displayed by color depending on the budget and the warning :
Blue: in the budget, Yellow: the warning and Red off budget.
If the warning (WARN threshold) is set at 0.90: Yellow color will be used when exceeding 90% of the budget.
Indicates the number of second image displayed on a computer screen (fps animation).