Similar to bug #1377227 "Speedy" Regression window (mozilla-central) Good: https://ftp.mozilla.org/pub/firefox/nightly/2017/05/2017-05-22-03-02-07-mozilla-central/ Bad: https://ftp.mozilla.org/pub/firefox/nightly/2017/05/2017-05-23-03-02-06-mozilla-central/ Pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=131e19a573e901fb4d01b471b11b7916420b9fee&tochange=388d81ed93fa640f91d155f36254667c734157cf Probably caused by: Bug #1372689 - Update tab strip button icons

The spec says icons shouldn't be full black: http://design.firefox.com/photon/visual/icons.html#color

FYI - "Open a new tab" & "List All Tabs" icons were fixed by patch from bug #1377184, so for now in this bug only "Tab bar scroll arrows" icon needs color tuning.

Comment on attachment 8908040 [details] Bug 1384686 - Use currentColor with a fill-opacity for toolbar button icons. https://reviewboard.mozilla.org/r/179724/#review185022 I think some animatable-boxes have been moved outside their toolbar (to avoid clipping by the tabs). It might be worth checking if currentColor is correctly working well in these situations (I haven't found issues myself when testing the patch, but worth double checking). ::: browser/themes/shared/downloads/indicator.inc.css:16 (Diff revision 3) > #downloads-indicator-progress-outer { > width: 16px; > height: 16px; > background-size: 16px; > - -moz-context-properties: fill; > background: url("chrome://browser/skin/downloads/download-icons.svg#default-bar") center no-repeat; browser/themes/shared/downloads/download-icons.svg needs fill-opacity="context-fill-opacity" set as well. ::: browser/themes/shared/icons/link.svg:7 (Diff revision 3) > - License, v. 2.0. If a copy of the MPL was not distributed with this > - file, You can obtain one at http://mozilla.org/MPL/2.0/. --> > <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> > - <rect fill-opacity="context-fill-opacity" fill="context-fill" x="7" y="3.286" width="2" height="9.429" rx="1" ry="1" transform="rotate(-45 8 8)"/> > - <path fill-opacity="context-fill-opacity" fill="context-fill" d="M2.354 4.522L4.485 2.39a.5.5 0 0 1 .711 0l3.19 3.19.014-.015a2 2 0 0 0 0-2.821L6.272.616a2 2 0 0 0-2.821 0L.616 3.451a2 2 0 0 0 0 2.821L2.744 8.4a1.993 1.993 0 0 0 2.8.02l-3.19-3.186a.5.5 0 0 1 0-.712z"/> > - <path fill-opacity="context-fill-opacity" fill="context-fill" d="M15.416 9.759L13.287 7.63a2 2 0 0 0-2.821 0l-.015.015 3.189 3.189a.5.5 0 0 1 0 .711l-2.132 2.132a.5.5 0 0 1-.711 0L7.61 10.49a1.993 1.993 0 0 0 .02 2.8l2.128 2.128a2 2 0 0 0 2.821 0l2.835-2.835a2 2 0 0 0 .002-2.824z"/> > + <rect fill="context-fill" fill-opacity="context-fill-opacity" x="7" y="3.286" width="2" height="9.429" rx="1" ry="1" transform="rotate(-45 8 8)"/> > + <path fill="context-fill" fill-opacity="context-fill-opacity" d="M2.354 4.522L4.485 2.39a.5.5 0 0 1 .711 0l3.19 3.19.014-.015a2 2 0 0 0 0-2.821L6.272.616a2 2 0 0 0-2.821 0L.616 3.451a2 2 0 0 0 0 2.821L2.744 8.4a1.993 1.993 0 0 0 2.8.02l-3.19-3.186a.5.5 0 0 1 0-.712z"/> > + <path fill="context-fill" fill-opacity="context-fill-opacity" d="M15.416 9.759L13.287 7.63a2 2 0 0 0-2.821 0l-.015.015 3.189 3.189a.5.5 0 0 1 0 .711l-2.132 2.132a.5.5 0 0 1-.711 0L7.61 10.49a1.993 1.993 0 0 0 .02 2.8l2.128 2.128a2 2 0 0 0 2.821 0l2.835-2.835a2 2 0 0 0 .002-2.824z"/> nit: use the root <svg> tag to avoid setting both attributes 3 times

Pushed by dgottwald@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/7de50f562f6f Use currentColor with a fill-opacity for toolbar button icons. r=ntim

I'm confirming that bug is fixed, starting in Mozilla Firefox Nightly 57.0a1 (2017-09-16), so I'm marking this bug as VERIFIED. Thanks. Follow-up is being tracked in bug #1400551.

Screenshots: https://screenshots.mattn.ca/compare/?oldProject=mozilla-central&oldRev=9071a20f3eaa804a439990b7596dbc16d52d1e20&newProject=mozilla-central&newRev=31992a5c3d64ade078accdaab8ac4ffb5e43a9d7