diff --git a/gtk/theme/HighContrast/_common.scss b/gtk/theme/HighContrast/_common.scss
index 1f8457322c..9b6cde1d5a 100644
--- a/gtk/theme/HighContrast/_common.scss
+++ b/gtk/theme/HighContrast/_common.scss
@@ -980,7 +980,10 @@ spinbutton {
         background-color: $bg_color;
       }
 
-      &:disabled { color: transparentize($insensitive_fg_color, 0.7); }
+      &:disabled,
+      &:backdrop:disabled {
+        color: transparentize($insensitive_fg_color, 0.7);
+      }
 
       &:active {
         background-color: $osd_bg_color;
@@ -994,7 +997,6 @@ spinbutton {
       }
 
       &:backdrop:disabled {
-        color: $insensitive_bg_color;
         background-image: none;
         border-style: none none none solid; // It is needed or it gets overridden
 
diff --git a/gtk/theme/HighContrast/gtk-contained-inverse.css b/gtk/theme/HighContrast/gtk-contained-inverse.css
index fadb1ce2d0..313980cb4c 100644
--- a/gtk/theme/HighContrast/gtk-contained-inverse.css
+++ b/gtk/theme/HighContrast/gtk-contained-inverse.css
@@ -405,13 +405,13 @@ spinbutton:not(.vertical) button:dir(rtl) { border-style: none solid none none;
 
 spinbutton:not(.vertical) button:hover { color: #fff; background-color: #000; }
 
-spinbutton:not(.vertical) button:disabled { color: rgba(128, 128, 128, 0.3); }
+spinbutton:not(.vertical) button:disabled, spinbutton:not(.vertical) button:backdrop:disabled { color: rgba(128, 128, 128, 0.3); }
 
 spinbutton:not(.vertical) button:active { background-color: rgba(0, 0, 0, 0.8); color: #fff; }
 
 spinbutton:not(.vertical) button:backdrop { color: #fff; background-color: transparent; border-color: rgba(115, 115, 115, 0.3); }
 
-spinbutton:not(.vertical) button:backdrop:disabled { color: #070707; background-image: none; border-style: none none none solid; }
+spinbutton:not(.vertical) button:backdrop:disabled { background-image: none; border-style: none none none solid; }
 
 spinbutton:not(.vertical) button:backdrop:disabled:dir(rtl) { border-style: none solid none none; }
 
diff --git a/gtk/theme/HighContrast/gtk-contained.css b/gtk/theme/HighContrast/gtk-contained.css
index e0e6a58e8e..c174d6c607 100644
--- a/gtk/theme/HighContrast/gtk-contained.css
+++ b/gtk/theme/HighContrast/gtk-contained.css
@@ -409,13 +409,13 @@ spinbutton:not(.vertical) button:dir(rtl) { border-style: none solid none none;
 
 spinbutton:not(.vertical) button:hover { color: #000; background-color: #fff; }
 
-spinbutton:not(.vertical) button:disabled { color: rgba(128, 128, 128, 0.3); }
+spinbutton:not(.vertical) button:disabled, spinbutton:not(.vertical) button:backdrop:disabled { color: rgba(128, 128, 128, 0.3); }
 
 spinbutton:not(.vertical) button:active { background-color: rgba(0, 0, 0, 0.8); color: #fff; }
 
 spinbutton:not(.vertical) button:backdrop { color: #000; background-color: transparent; border-color: rgba(141, 141, 141, 0.3); }
 
-spinbutton:not(.vertical) button:backdrop:disabled { color: white; background-image: none; border-style: none none none solid; }
+spinbutton:not(.vertical) button:backdrop:disabled { background-image: none; border-style: none none none solid; }
 
 spinbutton:not(.vertical) button:backdrop:disabled:dir(rtl) { border-style: none solid none none; }