--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -899,22 +899,21 @@ toolbarbutton.chevron > .toolbarbutton-i
 
 %include ../shared/UITour.inc.css
 
 #UITourHighlight {
   /* Below are some fixes for people without an X compositor on Linux.
      This is why we can't have nice things: */
   /* Animations don't repaint properly without an X compositor. */
   animation-name: none !important;
-  /* Opacity rounds to 0 or 1 on Linux without an X compositor so make the
-     background be transparent in that case by having all alpha values < 0.5 */
-  background-image: radial-gradient(50% 100%, rgba(0,149,220,0.3) 50%, rgba(0,149,220,0.49) 100%);
-  /* The highlight isn't anti-aliased without an X compositor so make it thicker.
-     Make it a darker color since we don't have the box-shadow in this case. */
-  border: 4px solid rgb(0,149,220);
+  /* Opacity rounds to 0 or 1 on Linux without an X compositor, making the
+     background color not visible. Anti-aliasing is not available either. Make a
+     thicker outline and cancel border-radius for that case. */
+     outline: 4px solid rgb(0,200,215);
+     border-radius: 0 !important;
 }
 
 #UITourTooltipDescription {
   font-size: 1.05rem;
 }
 
 #UITourTooltipClose {
   margin-inline-end: -4px;