Prevent the color extension from auto-loading

lib/main.js

@@ -426,6 +426,20 @@ function ConfigureMathJax() {
 
       });
 
+      //
+      //  Reset the color extension after `autoload-all`
+      //
+      if (MathJax.AuthorConfig.extensions.indexOf("TeX/color.js") == -1) {
+              MathJax.Hub.Register.StartupHook("TeX autoload-all Ready",function () {
+                var macros = MathJax.InputJax.TeX.Definitions.macros;
+                macros.color = "Color";
+                delete macros.textcolor;
+                delete macros.colorbox;
+                delete macros.fcolorbox;
+                delete macros.definecolor;
+              });
+            }
+
       //
       //  Start the typesetting queue when MathJax is ready
       //    (reseting the counters so that the initial math doesn't affect them)

test/issue175.js

@@ -0,0 +1,28 @@
+var tape = require('tape');
+var mjAPI = require("../lib/main.js");
+var jsdom = require('jsdom').jsdom;
+
+tape('color extension should be reset', function(t) {
+  t.plan(3);
+  mjAPI.start();
+  var tex = '\\colorbox{green}{x}';
+  var tex2 = '\\color{red}{x}x';
+
+  mjAPI.typeset({
+    math: tex,
+    format: "TeX",
+     mml: true
+  }, function(data) {
+    t.ok(data.errors, 'Color extension disabled');
+  });
+  mjAPI.typeset({
+    math: tex2,
+    format: "TeX",
+     mml: true
+  }, function(data) {
+    var document = jsdom(data.mml);
+    var mstyle = document.defaultView.document.querySelector('mstyle');
+    t.ok(document.defaultView.document.querySelectorAll('mi')[0].parentNode === mstyle, 'Color macro behaves correctly (1 of 2)');
+    t.notOk(document.defaultView.document.querySelectorAll('mi')[1].parentNode === mstyle, 'Color macro behaves correctly (2 of 2)');
+  });
+});