--- a/devtools/client/themes/images/grid.svg
+++ b/devtools/client/themes/images/grid.svg
@@ -1,6 +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 width="16" height="16" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg" stroke="#696969">
-  <path fill="none" fill-rule="evenodd" stroke-linecap="round" stroke-linejoin="round" d="M2 4h12M2 8h12M2 12h12M4 14V2M8 14V2M12 14V2"/>
+<svg width="12" height="12" viewBox="0 0 12 12" xmlns="http://www.w3.org/2000/svg" stroke="#696969">
+  <path fill="none" d="M1 2.5h9m-9 3h9m-9 3h9M2.5 1v9m3-9v9m3-9v9"/>
 </svg>

--- a/devtools/client/themes/rules.css
+++ b/devtools/client/themes/rules.css
@@ -411,17 +411,16 @@
   margin-top: -1px;
   margin-inline-end: 5px;
   display: inline-block;
   position: relative;
 }
 
 .ruleview-grid {
   background: url("chrome://devtools/skin/images/grid.svg");
-  background-size: 1em;
   border-radius: 0;
 }
 
 .ruleview-colorswatch::before {
   content: '';
   background-color: #eee;
   background-image: linear-gradient(45deg, #ccc 25%, transparent 25%, transparent 75%, #ccc 75%, #ccc),
                     linear-gradient(45deg, #ccc 25%, transparent 25%, transparent 75%, #ccc 75%, #ccc);