Mine was 2 dark blue bars when they had my committee letter packet. It changed to 3 dark blue bars after I emailed them and they "checked off" my committee letter packet as having fulfilled all LOR requirements. I think it takes some time between them changing the letters from incomplete to complete, ultimately reflecting 4 dark blue bars - AKA file being complete and ready to review.
My response email said this when I initially had 2 dark blue bars: "We've updated your record to reflect the multiple letters received in that packet and your file is now complete and ready for review with our committee" and now it has 3 dark blue bars and my portal says:
"Your submitted materials are under initial review with Admissions staff for completeness. If your file is complete, you will be moved to the next phase of the review process with the Faculty Committee on Admissions. If you are noted to be missing any required items, those items will be updated on your application checklist in the Application Materials tab."