Progress/status bar/meter style looks bad

• on far left when updating/downloading/installing is starting there is some kinda of vertical bar with another shade of blue

• on far right when updating/downloading/installing is nearly ending there is some kinda of vertical bar with another shade of blue

• black "Downloading" text with white glow is kinda hard to read when progress/status bar/meter becomes more and more blue

• "X" (cancel) button is kinda hard to see when progress/status bar/meter becomes more and more blue

NI UX because color/contrast yuck.

Can someone tell me what's in the dropdown?
And why we need it?

I recommend to simplify and align this experience with the rest of Firefox. Re-use the animation for loading tabs and downloading (adding) add-ons. The end state should look this one -> https://user-images.githubusercontent.com/217628/43139375-df62b02e-8f51-11e8-9254-e4f3eac5db0d.gif

Another thing could be re-use progress animation of download button or items in download button.

We agreed to address this in the future card design, which is soon.

I can't reproduce it anymore after landing patch from bug #1555012, so I'm marking this bug as FIXED.