trying to fix the "my model is all black" issue.

blockly/core/xml.js

@@ -265,8 +265,13 @@ Blockly.Xml.domToWorkspace = function(workspace, xml) {
     if (xmlChild.nodeName.toLowerCase() == 'color') {
       var col = xmlChild.getAttribute('rgba');
       var colA = col.split(',');
-      Blockscad.setColor(colA[0],colA[1],colA[2]);
-      found_color = true;
+      if (colA.length == 3)
+      if (colA[0] >= 0 && colA[0] < 255)
+      if (colA[1] >= 0 && colA[1] < 255)
+      if (colA[2] >= 0 && colA[2] < 255) {
+        Blockscad.setColor(colA[0],colA[1],colA[2]);
+        found_color = true;
+      }
     }
     if (xmlChild.nodeName.toLowerCase() == 'block') {
       var block = Blockly.Xml.domToBlock(workspace, xmlChild);

blockscad/blockscad.js

@@ -293,6 +293,7 @@ Blockscad.init = function() {
   });
 
   // add "default color" picker to viewer
+  // r,g,b is expecting to get color values between 0 and 255 for r,g,b
 
   Blockscad.setColor = function(r,g,b) {
     // console.log("in setColor.  rgb:" + r + ";" + g + ';' + b);