Simple modification of the Dust theme (murrine) included with Ubuntu.

This theme supports custom colors, controls are clearly visible with dark color schemes, you can use the tab key to navigate through the controls an actually see which control is highlighted (which not supported by several themes and the reason why I did this modification).

A few parameters have been modified to support dark color schemes, however, you cannot use bright inputs with dark windows or viceversa, as seen in the Ubuntu Studio color scheme.