--- /dev/null
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+ - 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 height="0" xmlns="http://www.w3.org/2000/svg">
+ <filter id="active-icon-state"><!-- make every icon be fully black, but keep alpha channel -->
+ <feColorMatrix in="SourceGraphic" type="matrix"
+ values="0 0 0 0 0
+ 0 0 0 0 0
+ 0 0 0 0 0
+ 0 0 0 1 0"/>
+ </filter>
+ <filter id="disabled-icon-state"><!-- move any icon to #808080 / rgb(128,128,128), keeping alpha channel -->
+ <feColorMatrix in="SourceGraphic" type="matrix" color-interpolation-filters="sRGB"
+ values="0 0 0 0 0.50
+ 0 0 0 0 0.50
+ 0 0 0 0 0.50
+ 0 0 0 1 0"/>
+ </filter>
+</svg>