I would love to use the latest version of micron.  I have been using the 2012 version for 3 years.  I downloaded the new version, and it seemed to be working fine until I tried to add a second layer.  A color came up and covered the whole image box, and the drop-down for color said "grayscale."  Only "Background" and one layer showed up in the the layer drop-down menu.  Has anyone else had this problem?

I can confirm there is an issue specific to the MacOS Cocoa widgetset when you load an overlay with the same name more than once. By default, Cocoa applications require each item in a popup list to have a unique name. I am evaluating a couple solutions, but for the time being you can test out this version (About will report this as version 2May2016b") which does not have the problem:
  http://people.cas.sc.edu/rorden/SW/