diff --git a/blocks_vertical/looks.js b/blocks_vertical/looks.js
index 66482f0ef3..d0f0a12b90 100644
--- a/blocks_vertical/looks.js
+++ b/blocks_vertical/looks.js
@@ -18,15 +18,8 @@
  * limitations under the License.
  */
 
-'use strict';
-
-goog.provide('Blockly.Blocks.looks');
-
-goog.require('Blockly.Blocks');
-goog.require('Blockly.Colours');
-goog.require('Blockly.constants');
-goog.require('Blockly.ScratchBlocks.VerticalExtensions');
-
+import * as Blockly from 'blockly/core';
+import {Categories} from '../src/categories.js';
 
 Blockly.Blocks['looks_sayforsecs'] = {
   /**
@@ -46,7 +39,7 @@ Blockly.Blocks['looks_sayforsecs'] = {
           "name": "SECS"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -66,7 +59,7 @@ Blockly.Blocks['looks_say'] = {
           "name": "MESSAGE"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -90,7 +83,7 @@ Blockly.Blocks['looks_thinkforsecs'] = {
           "name": "SECS"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -110,7 +103,7 @@ Blockly.Blocks['looks_think'] = {
           "name": "MESSAGE"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -124,7 +117,7 @@ Blockly.Blocks['looks_show'] = {
   init: function() {
     this.jsonInit({
       "message0": Blockly.Msg.LOOKS_SHOW,
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -138,7 +131,7 @@ Blockly.Blocks['looks_hide'] = {
   init: function() {
     this.jsonInit({
       "message0": Blockly.Msg.LOOKS_HIDE,
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -154,7 +147,7 @@ Blockly.Blocks['looks_hideallsprites'] = {
   init: function() {
     this.jsonInit({
       "message0": Blockly.Msg.LOOKS_HIDEALLSPRITES,
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -187,7 +180,7 @@ Blockly.Blocks['looks_changeeffectby'] = {
           "name": "CHANGE"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -220,7 +213,7 @@ Blockly.Blocks['looks_seteffectto'] = {
           "name": "VALUE"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -234,7 +227,7 @@ Blockly.Blocks['looks_cleargraphiceffects'] = {
   init: function() {
     this.jsonInit({
       "message0": Blockly.Msg.LOOKS_CLEARGRAPHICEFFECTS,
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -254,7 +247,7 @@ Blockly.Blocks['looks_changesizeby'] = {
           "name": "CHANGE"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -274,7 +267,7 @@ Blockly.Blocks['looks_setsizeto'] = {
           "name": "SIZE"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -288,7 +281,7 @@ Blockly.Blocks['looks_size'] = {
   init: function() {
     this.jsonInit({
       "message0": Blockly.Msg.LOOKS_SIZE,
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "checkboxInFlyout": true,
       "extensions": ["colours_looks", "output_number"]
     });
@@ -318,7 +311,7 @@ Blockly.Blocks['looks_changestretchby'] = {
           "name": "CHANGE"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -340,7 +333,7 @@ Blockly.Blocks['looks_setstretchto'] = {
           "name": "STRETCH"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -364,11 +357,7 @@ Blockly.Blocks['looks_costume'] = {
           ]
         }
       ],
-      "colour": Blockly.Colours.looks.secondary,
-      "colourSecondary": Blockly.Colours.looks.secondary,
-      "colourTertiary": Blockly.Colours.looks.tertiary,
-      "colourQuaternary": Blockly.Colours.looks.quaternary,
-      "extensions": ["output_string"]
+      "extensions": ["colours_looks", "output_string"]
     });
   }
 };
@@ -387,7 +376,7 @@ Blockly.Blocks['looks_switchcostumeto'] = {
           "name": "COSTUME"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -401,7 +390,7 @@ Blockly.Blocks['looks_nextcostume'] = {
   init: function() {
     this.jsonInit({
       "message0": Blockly.Msg.LOOKS_NEXTCOSTUME,
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -421,7 +410,7 @@ Blockly.Blocks['looks_switchbackdropto'] = {
           "name": "BACKDROP"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -445,11 +434,7 @@ Blockly.Blocks['looks_backdrops'] = {
           ]
         }
       ],
-      "colour": Blockly.Colours.looks.secondary,
-      "colourSecondary": Blockly.Colours.looks.secondary,
-      "colourTertiary": Blockly.Colours.looks.tertiary,
-      "colourQuaternary": Blockly.Colours.looks.quaternary,
-      "extensions": ["output_string"]
+      "extensions": ["colours_looks", "output_string"]
     });
   }
 };
@@ -472,7 +457,7 @@ Blockly.Blocks['looks_gotofrontback'] = {
           ]
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -500,7 +485,7 @@ Blockly.Blocks['looks_goforwardbackwardlayers'] = {
           "name": "NUM"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -524,7 +509,7 @@ Blockly.Blocks['looks_backdropnumbername'] = {
           ]
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "checkboxInFlyout": true,
       "extensions": ["colours_looks", "output_number"]
     });
@@ -549,7 +534,7 @@ Blockly.Blocks['looks_costumenumbername'] = {
           ]
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "checkboxInFlyout": true,
       "extensions": ["colours_looks", "output_number"]
     });
@@ -570,7 +555,7 @@ Blockly.Blocks['looks_switchbackdroptoandwait'] = {
           "name": "BACKDROP"
         }
       ],
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
@@ -584,7 +569,7 @@ Blockly.Blocks['looks_nextbackdrop'] = {
   init: function() {
     this.jsonInit({
       "message0": Blockly.Msg.LOOKS_NEXTBACKDROP_BLOCK,
-      "category": Blockly.Categories.looks,
+      "category": Categories.looks,
       "extensions": ["colours_looks", "shape_statement"]
     });
   }
diff --git a/src/index.js b/src/index.js
index 1a47656305..22fd9f0a64 100644
--- a/src/index.js
+++ b/src/index.js
@@ -8,6 +8,7 @@ import '../blocks_common/math.js';
 import '../blocks_vertical/vertical_extensions.js';
 import '../blocks_vertical/control.js';
 import '../blocks_vertical/event.js';
+import '../blocks_vertical/looks.js';
 import '../blocks_vertical/motion.js';
 import '../blocks_vertical/operators.js';