diff --git a/core/field_colour.js b/core/field_colour.js
index 1847bb9a9..c30f2bb76 100644
--- a/core/field_colour.js
+++ b/core/field_colour.js
@@ -82,12 +82,6 @@ Blockly.FieldColour.DEFAULT_WIDTH = 16;
  */
 Blockly.FieldColour.DEFAULT_HEIGHT = 12;
 
-/**
- * Regex that defines the form of a colour string.
- * @type {RegExp}
- */
-Blockly.FieldColour.COLOUR_REGEX = new RegExp('#[0-9a-fA-F]{6}');
-
 /**
  * Serializable fields are saved by the XML renderer, non-serializable fields
  * are not. Editable fields should also be serializable.