When added the short-code of a Widget from the WP Metrics Master plugin to your WP Page you can add a parameter onto the short-code that will make the background transparent.

[wpmm_widgets id="1473" transparent="1"]

In the example above the variable 'transparent' is given a value '1' which will make the background of the input area of the Widget transparent.

This can be added to any version of the widget that you are using.