As is shown in this new mockup from Stephen: http://people.mozilla.org/~shorlander/mockups-interactive/awesomebar-results/awesomeBar-results-tabOrdering.html

Working on this as part of bug 1295458.

I'm narrowing this bug's focus specifically to the one-off buttons' new gray background color, since bug 1295458 takes care of the hover and selection colors. That's the only thing left to do regarding the one-offs in Stephen's mockup in comment 0. The color should match the gray color of the one-offs header.

Stephen, what's the goal of this change? My impression is that it makes the one-off buttons less noticeable/discoverable, and the icons harder to 'read', due to a lower contrast between them and their background.

The goal is to visually separate the primary actions (top: results) from the secondary actions (bottom: non-default search engines). It also visually groups these two sections. I am not sure it really affect emphasis. It's unlikely to affect discoverablily one way or the other.

After trying the patch, I think it looks OK on the awesomebar panel, but I dislike its appearance on the searchbar panel http://i.imgur.com/jRdD8Rt.png And it's even worse when the searchbar is empty and the user just clicks the glass icon: all of the panel's background is gray in this case http://i.imgur.com/pRUyL7z.png . If we do go ahead with this change, I think we'll need to also apply it to open search items as the lighter item looks like a bug here: http://i.imgur.com/AVYhS9c.png. Stephen, are these screenshots what you expect?

Fixes add-engine and the non-compact settings buttons.

I am fine with the appearance. I do agree that the add search item row should match.

Stephen commented in comment 10, wanted to make sure you saw it.

Comment on attachment 8854363 [details] Bug 1295460 - Update the background color of the one-off search buttons. https://reviewboard.mozilla.org/r/126298/#review133818

Pushed by dwillcoxon@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/71005756f3fb Update the background color of the one-off search buttons. r=florian

Verified as fixed using the latest Nightly 55.0a1 (Build ID: 20170419030223) on Windows 10 x64, Ubuntu 16.04 x64 and Mac OS X 10.12 - the background color of the one-off search buttons is updated as in the mock-up from the Description. During verification, I observed some painting issue in the search bar on Ubuntu, logged Bug 1357800 to cover this.

Based on Comment 15, marking this as Verified Fixed.