Reproducible on: * Nightly 42.0a1 (2015-07-29) * Aurora 41.0a2 (2015-07-29) * Beta 40.0b8 (20150727174134) Affected platforms: Windows 10 Pro x64 (Build 10240) Steps to reproduce: 1. Launch Firefox. 2. Open several new tabs until there's an overflow visible along with its controls. 3. Check the separators displayed for the overflow navigation buttons. Expected result: The separators from the overflow controls are solid and in line with regular tab separators. Actual result: The overflow separators are still reflecting the old design. Note: * This issue is not a regression.

If we want this for 41 we need a design of how we're supposed to resolve this.

I tried a couple of things in the inspector (solid background etc), but wasn't quite happy with the results so far. Perhaps Stephen already has something in his endless bag of mockups :)

FWIW, just removing the dark gradients on the left and right makes it look better (though not perfect)

Bug 1188294 fixed a weird overlap issue, but the gradient is still fodder to fix.

Not targeting Firefox 41 any longer since it's still not clear how this should be addressed.

The Photon project has since removed the button gradient for us.