diff --git a/lib/carto/torque-reference.js b/lib/carto/torque-reference.js
index 5f300d4..dc196eb 100644
--- a/lib/carto/torque-reference.js
+++ b/lib/carto/torque-reference.js
@@ -25,7 +25,10 @@ var _mapnik_reference_latest = {
                 ["x-gradient", 0],
                 ["y-gradient", 0],
                 ["invert", 0],
-                ["sharpen", 0]
+                ["sharpen", 0],
+                ["colorize-alpha", -1],
+                ["color-to-alpha", 1],
+                ["scale-hsla", 8]
             ],
             "doc": "A list of image filters."
         },
@@ -160,7 +163,10 @@ var _mapnik_reference_latest = {
                     ["x-gradient", 0],
                     ["y-gradient", 0],
                     ["invert", 0],
-                    ["sharpen", 0]
+                    ["sharpen", 0],
+                    ["colorize-alpha", -1],
+                    ["color-to-alpha", 1],
+                    ["scale-hsla", 8]
                 ],
                 "doc": "A list of image filters."
             },
diff --git a/lib/carto/tree/value.js b/lib/carto/tree/value.js
index a02353d..7e74e76 100644
--- a/lib/carto/tree/value.js
+++ b/lib/carto/tree/value.js
@@ -37,6 +37,11 @@ tree.Value.prototype = {
       } else if (val.is === 'field') {
         // replace [variable] by ctx['variable']
         v = v.replace(/\[(.*)\]/g, "data['$1']");
+      }else if (val.is === 'call') {
+        v = JSON.stringify({
+            name: val.name,
+            args: val.args
+        })
       }
       return "_value = " + v + ";";
     }
diff --git a/test/rendering_js.test.js b/test/rendering_js.test.js
index a6ae419..b7fa962 100644
--- a/test/rendering_js.test.js
+++ b/test/rendering_js.test.js
@@ -74,6 +74,17 @@ describe('RenderingJS', function() {
     assert(layer0.getSymbolizers()[1] === 'line');
   });
 
+  it ("colorize should return a list of colours in same order", function() {
+    var style = '#test { image-filters: colorize-alpha(blue, cyan, green, yellow, orange, red); }';
+    var shader = (new carto.RendererJS({ debug: true })).render(style);
+    var layer0 = shader.getLayers()[0];
+    var st = layer0.getStyle({ value: 1 }, {"frame-offset": 0, "zoom": 3});
+    var expectedColours = [[0, 0, 255], [0, 255, 255], [0, 128, 0], [255, 255, 0], [255, 165, 0], [255, 0, 0]];
+    for (var i = 0; i < st["image-filters"].args; i++){
+      assert (st["image-filters"].args[i].rgb === expectedColours[i]);
+    }
+  });
+
   it ("should return list of marker-files", function(){
     var css = [
           'Map {',