Call forceRerender instead of setText

core/block_svg.js

@@ -1032,9 +1032,10 @@ Blockly.BlockSvg.prototype.updateColour = function() {
   }
 
   // Bump every dropdown to change its colour.
+  // TODO (#1456)
   for (var x = 0, input; input = this.inputList[x]; x++) {
     for (var y = 0, field; field = input.fieldRow[y]; y++) {
-      field.setText(null);
+      field.forceRerender();
     }
   }
 };

core/field_dropdown.js

@@ -115,10 +115,8 @@ Blockly.FieldDropdown.prototype.init = function() {
       ' ' + Blockly.FieldDropdown.ARROW_CHAR));
 
   Blockly.FieldDropdown.superClass_.init.call(this);
-  // Force a reset of the text to add the arrow.
-  var text = this.text_;
-  this.text_ = null;
-  this.setText(text);
+  // Make sure the arrow gets rendered.
+  this.forceRerender();
 };
 
 /**