diff --git a/core/toolbox/category.ts b/core/toolbox/category.ts
index 653d848ec..06f219e5e 100644
--- a/core/toolbox/category.ts
+++ b/core/toolbox/category.ts
@@ -137,7 +137,7 @@ export class ToolboxCategory
       'icon': 'blocklyToolboxCategoryIcon',
       'label': 'blocklyTreeLabel',
       'contents': 'blocklyToolboxCategoryGroup',
-      'selected': 'blocklyTreeSelected',
+      'selected': 'blocklyToolboxSelected',
       'openicon': 'blocklyToolboxCategoryIconOpen',
       'closedicon': 'blocklyTreeIconClosed',
     };
@@ -659,7 +659,7 @@ export type CssConfig = ToolboxCategory.CssConfig;
 
 /** CSS for Toolbox.  See css.js for use. */
 Css.register(`
-.blocklyToolboxCategory:not(.blocklyTreeSelected):hover {
+.blocklyToolboxCategory:not(.blocklyToolboxSelected):hover {
   background-color: rgba(255, 255, 255, .2);
 }
 
@@ -700,11 +700,11 @@ Css.register(`
   background-position: 0 -1px;
 }
 
-.blocklyTreeSelected>.blocklyTreeIconClosed {
+.blocklyToolboxSelected>.blocklyTreeIconClosed {
   background-position: -32px -17px;
 }
 
-.blocklyToolboxDiv[dir="RTL"] .blocklyTreeSelected>.blocklyTreeIconClosed {
+.blocklyToolboxDiv[dir="RTL"] .blocklyToolboxSelected>.blocklyTreeIconClosed {
   background-position: 0 -17px;
 }
 
@@ -712,7 +712,7 @@ Css.register(`
   background-position: -16px -1px;
 }
 
-.blocklyTreeSelected>.blocklyToolboxCategoryIconOpen {
+.blocklyToolboxSelected>.blocklyToolboxCategoryIconOpen {
   background-position: -16px -17px;
 }
 
@@ -727,7 +727,7 @@ Css.register(`
   cursor: url("<<<PATH>>>/handdelete.cur"), auto;
 }
 
-.blocklyTreeSelected .blocklyTreeLabel {
+.blocklyToolboxSelected .blocklyTreeLabel {
   color: #fff;
 }
 `);