--- a/browser/themes/shared/controlcenter/panel.inc.css
+++ b/browser/themes/shared/controlcenter/panel.inc.css
@@ -377,39 +377,40 @@ description#identity-popup-content-verif
 .identity-popup-permission-remove-button {
   -moz-appearance: none;
   margin: 0;
   border-width: 0;
   border-radius: 50%;
   min-width: 0;
   padding: 2px;
   background-color: transparent;
+  opacity: 0.6;
 }
 
 .identity-popup-permission-remove-button > .button-box {
   padding: 0;
 }
 
 .identity-popup-permission-remove-button > .button-box > .button-icon {
   margin: 0;
   width: 16px;
   height: 16px;
   list-style-image: url(chrome://browser/skin/panel-icon-cancel.svg);
   -moz-context-properties: fill;
-  fill: graytext;
+  fill: currentColor;
 }
 
 .identity-popup-permission-remove-button > .button-box > .button-text {
   display: none;
 }
 
 /* swap foreground / background colors on hover */
 .identity-popup-permission-remove-button:not(:-moz-focusring):hover {
-  background-color: graytext;
+  background-color: currentColor;
 }
 
 .identity-popup-permission-remove-button:not(:-moz-focusring):hover > .button-box > .button-icon {
-  fill: -moz-field;
+  fill: var(--arrowpanel-background);
 }
 
 .identity-popup-permission-remove-button:not(:-moz-focusring):hover:active {
-  background-color: -moz-fieldtext;
+  opacity: 0.8;
 }

--- a/browser/themes/shared/customizableui/panelUI.inc.css
+++ b/browser/themes/shared/customizableui/panelUI.inc.css
@@ -856,19 +856,20 @@ panelview .toolbarbutton-1,
 
 .subviewbutton[shortcut]::after {
   content: attr(shortcut);
   float: right;
   color: GrayText;
 }
 
 .PanelUI-subView .subviewbutton-nav::after {
-  -moz-context-properties: fill;
+  -moz-context-properties: fill, fill-opacity;
   content: url(chrome://browser/skin/back-12.svg);
-  fill: GrayText;
+  fill: currentColor;
+  fill-opacity: 0.6;
   float: right;
   transform: translateY(1px);
 }
 
 #main-window:not([customizing]) .subviewbutton-nav[disabled=true]::after {
   opacity: 0.4;
 }
 
@@ -887,20 +888,20 @@ panelview .toolbarbutton-1,
 }
 
 .subviewbutton[type="highlight-history"]::after {
   content: url("chrome://browser/skin/history.svg");
 }
 
 .subviewbutton[type="highlight-bookmark"]::after,
 .subviewbutton[type="highlight-history"]::after {
-  -moz-context-properties: fill;
-  fill: GrayText;
+  -moz-context-properties: fill, fill-opacity;
+  fill: currentColor;
+  fill-opacity: 0.4;
   float: right;
-  opacity: .5;
   /* Centers the icon and resizes it to 12px square. */
   transform: translateY(2px) scaleX(.75);
 }
 
 /* This is a <label> but it should fit in with the menu font- and colorwise. */
 #PanelUI-characterEncodingView-autodetect-label {
   font: menu;
   color: inherit;
@@ -1257,25 +1258,26 @@ toolbaritem[overflowedItem=true],
 }
 
 .widget-overflow-list .toolbarbutton-1 {
   -moz-box-align: center;
   -moz-box-orient: horizontal;
 }
 
 .widget-overflow-list .subviewbutton-nav:-moz-locale-dir(ltr)::after {
-    transform: scaleX(-1);
+  transform: scaleX(-1);
 }
 
 .widget-overflow-list .subviewbutton-nav::after {
-    margin-inline-start: 10px;
-    -moz-context-properties: fill;
-    content: url(chrome://browser/skin/back-12.svg);
-    fill: GrayText;
-    float: right;
+  margin-inline-start: 10px;
+  -moz-context-properties: fill, fill-opacity;
+  content: url(chrome://browser/skin/back-12.svg);
+  fill: currentColor;
+  fill-opacity: 0.6;
+  float: right;
 }
 
 toolbarpaletteitem[place="menu-panel"] > .subviewbutton-nav::after {
   opacity: 0.5;
 }
 
 .widget-overflow-list .toolbarbutton-1:not(.toolbarbutton-combined) > .toolbarbutton-text {
   text-align: start;
@@ -1537,35 +1539,36 @@ menuitem[checked="true"].subviewbutton >
 
 .subviewbutton.download > .toolbarbutton-text > .status-text {
   color: GrayText;
   font-size: .9em;
 }
 
 .subviewbutton.download > .action-button {
   -moz-appearance: none; /* To avoid native Windows hover styling */
-  -moz-context-properties: fill;
+  -moz-context-properties: fill, fill-opacity;
   fill: currentColor;
+  fill-opacity: 1;
 %ifdef XP_MACOSX
   list-style-image: url("chrome://browser/skin/search-glass.svg");
 %else
   list-style-image: url("chrome://browser/skin/folder.svg");
 %endif
   /* Measurement to vertically center this button: 1 line of text minus half of 4px top margin. */
   margin: calc(1em - 2px) 0 0;
   padding: 4px;
 }
 
 .subviewbutton.download[retryLabel] > .action-button {
   list-style-image: url("chrome://browser/skin/reload.svg");
 }
 
 .subviewbutton.download:not([openLabel]):not([retryLabel]) > .action-button {
-  fill: GrayText;
-  opacity: .5;
+  fill: currentColor;
+  fill-opacity: 0.4;
 }
 
 .subviewbutton.download:-moz-any([openLabel],[retryLabel]) > .action-button@buttonStateHover@ {
   background-color: var(--arrowpanel-dimmed-further);
 }
 
 .subviewbutton.download:-moz-any([openLabel],[retryLabel]) > .action-button@buttonStateActive@ {
   background-color: var(--arrowpanel-dimmed-even-further);

--- a/browser/themes/shared/notification-icons.inc.css
+++ b/browser/themes/shared/notification-icons.inc.css
@@ -1,18 +1,19 @@
 %if 0
 /* 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/. */
 %endif
 
 .popup-notification-icon,
 .identity-popup-permission-icon {
-  -moz-context-properties: fill;
-  fill: GrayText;
+  -moz-context-properties: fill, fill-opacity;
+  fill: currentColor;
+  fill-opacity: 0.6;
 }
 
 #notification-popup-box {
   padding: 5px 0px;
   margin: -5px 0px;
   margin-inline-end: -5px;
   padding-inline-end: 5px;
 }

--- a/browser/themes/windows/customizableui/menu-arrow.svg
+++ b/browser/themes/windows/customizableui/menu-arrow.svg
@@ -1,7 +1,6 @@
 <!-- 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 xmlns="http://www.w3.org/2000/svg"
-     height="16" width="16" viewBox="0 0 16 16">
-  <path fill="context-fill" d="m 6,4 0,8 5,-4 z"/>
+<svg xmlns="http://www.w3.org/2000/svg" height="16" width="16" viewBox="0 0 16 16">
+  <path fill="context-fill" fill-opacity="context-fill-opacity" d="m 6,4 0,8 5,-4 z"/>
 </svg>

--- a/browser/themes/windows/customizableui/panelUI.css
+++ b/browser/themes/windows/customizableui/panelUI.css
@@ -43,30 +43,24 @@ menuitem[type="checkbox"].subviewbutton 
   /* This is 16px for an icon + 3px for its margins + 1px for its padding +
    * 2px for its border, see above */
   min-height: 22px;
 }
 
 menu.subviewbutton > .menu-right {
   -moz-appearance: none;
   list-style-image: url(chrome://browser/skin/customizableui/menu-arrow.svg);
-  -moz-context-properties: fill;
-  fill: MenuText;
+  -moz-context-properties: fill, fill-opacity;
+  fill: currentColor;
   /* Reset the rect we inherit from the button: */
   -moz-image-region: auto;
 }
 
 menu[disabled="true"].subviewbutton > .menu-right {
-  fill: GrayText;
-}
-
-@media (-moz-windows-default-theme: 0) {
-  menu[_moz-menuactive].subviewbutton > .menu-right {
-    fill: HighlightText;
-  }
+  fill-opacity: 0.6;
 }
 
 menu.subviewbutton > .menu-right:-moz-locale-dir(rtl) {
   transform: scaleX(-1);
 }
 
 /* Win8 and beyond. */
 @media not all and (-moz-os-version: windows-win7) {