diff --git a/core/modules/filters/colour-ops.js b/core/modules/filters/colour-ops.js
new file mode 100644
index 000000000..3ce9d1dca
--- /dev/null
+++ b/core/modules/filters/colour-ops.js
@@ -0,0 +1,41 @@
+/*\
+title: $:/core/modules/filters/colour-ops.js
+type: application/javascript
+module-type: filteroperator
+
+Filter operators for colour operations
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+var Color = require("$:/core/modules/utils/dom/color.js").Color;
+
+exports["colour-lighten"] = makeColourOperator(function (c, operator, operands) {
+	return c.lighten($tw.utils.parseNumber(operator.operand));
+});
+
+exports["colour-darken"] = makeColourOperator(function (c, operator, operands) {
+	return c.darken($tw.utils.parseNumber(operator.operand));
+});
+
+function makeColourOperator(fn) {
+	return function (source, operator, options) {
+		var results = [];
+		source(function (tiddler, title) {
+			var c = $tw.utils.parseCSSColorObject(title);
+			if (c) {
+				c = fn(c, operator, options);
+				results.push(c.display().toString());
+			} else {
+				results.push("");
+			}
+		});
+		return results;
+	};
+}
+
+})();
diff --git a/core/modules/utils/dom/color-utils.js b/core/modules/utils/dom/color-utils.js
index f4e119127..74e533a37 100644
--- a/core/modules/utils/dom/color-utils.js
+++ b/core/modules/utils/dom/color-utils.js
@@ -12,14 +12,13 @@ Color.js related utilities
 /*global $tw: false */
 "use strict";
 
+var Color = require("$:/core/modules/utils/dom/color.js").Color;
+
+/*
+For backwards compatibility
+*/
 exports.parseCSSColor = function(colourString) {
-	var Color = require("$:/core/modules/utils/dom/color.js").Color,
-		c = null;
-	try {
-		c = new Color(colourString);
-	} catch(e) {
-		// Do nothing on an error
-	}
+	var c = exports.parseCSSColorObject(colourString);
 	if(c) {
 		var rgb = c.srgb;
 		return [rgb[0],rgb[1],rgb[2],c.alpha];
@@ -28,4 +27,19 @@ exports.parseCSSColor = function(colourString) {
 	}
 };
 
+
+/*
+Preferred way to parse a Color.js colour
+*/
+exports.parseCSSColorObject = function(colourString) {
+	var Color = require("$:/core/modules/utils/dom/color.js").Color,
+		c = null;
+	try {
+		c = new Color(colourString);
+	} catch(e) {
+		// Return null if there is an error
+	}
+	return c;
+};
+
 })();
diff --git a/editions/test/tiddlers/tests/data/operators/colour/ColourDarken.tid b/editions/test/tiddlers/tests/data/operators/colour/ColourDarken.tid
new file mode 100644
index 000000000..7801d1c34
--- /dev/null
+++ b/editions/test/tiddlers/tests/data/operators/colour/ColourDarken.tid
@@ -0,0 +1,18 @@
+title: Operators/Colour/ColourDarken
+description: Darken colour function
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Output
+
+\parsermode inline
+\import [subfilter{$:/core/config/GlobalImportFilter}]
+<$text text={{{ [subfilter{Filter}] }}}/>
++
+title: Filter
+
+[function[colour],[primary]colour-darken[0.5]]
++
+title: ExpectedResult
+
+#0f1d77
\ No newline at end of file
diff --git a/editions/test/tiddlers/tests/data/operators/colour/ColourLighten.tid b/editions/test/tiddlers/tests/data/operators/colour/ColourLighten.tid
new file mode 100644
index 000000000..967215e52
--- /dev/null
+++ b/editions/test/tiddlers/tests/data/operators/colour/ColourLighten.tid
@@ -0,0 +1,18 @@
+title: Operators/Colour/ColourLighten
+description: Lighten colour function
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Output
+
+\parsermode inline
+\import [subfilter{$:/core/config/GlobalImportFilter}]
+<$text text={{{ [subfilter{Filter}] }}}/>
++
+title: Filter
+
+[function[colour],[primary]colour-lighten[0.5]]
++
+title: ExpectedResult
+
+#c6dbff
\ No newline at end of file