Comment to Mix "Xenon"- for "Protean" template.
It is not possible to install a Mix directly from the Storefront!
1) Save the .zip file extension to the desktop (From the store!).
2) To unzip all the contents of the zipped folder, press and hold (or right-click) the folder, select Extract Files...
3) Open the "Documentation" folder, double-click index.html.
4) Follow the instructions.