Question about Theme Switcher Plugin

I'm just curious about the Theme Switcher Plugin. Is there any possibility that it can be automated per user/session? I want it so when a new unique user enters our site the theme changes every time.

The plugin works and switched theme but makes the page load. I want it automated and the randomise each time a user enters the site. For example, One person views site and the theme is green and then someone else enters the site and the theme is pink. Is it possible or is there any workaround for this?