To use my theme, replace the xrc folder in your Hugin installation
(usually C:\Program Files\Hugin\share\hugin) with the dark theme xrc folder linked
here. To make your own modifications to the background color of a given panel,
open the appropriate XRC file (just try a bunch) in any text editor and
search for
<bg># . What comes after the # is the color in hex encoding. I used #A9A9A9 which is a medium grey. You can use
this site to find a color you like and its corresponding hex encoding.