Board Thread:Support Requests - Getting Technical/@comment-31246436-20161122151009/@comment-9605025-20161125230340

You have two templates. Template:Person is what users will invoke when creating an infobox. It takes in all the information that is needed. Template:Person then passes all of the values, unaltered, to a second template. In TableWiz's example, this second template is called Template:Default. Template:Default takes in one extra parameter compared to Template:Person. This extra parameter is used to set the theme used for the infobox and thus the background color of the image's cell. Template:Person is responsible for determining which theme to pass to Template: Default and does so based on whether or not a value was provided for the image name. Two changes I would make. This way, only non-whitespace will been interpreted as an image name.
 * title_bg =

Also, rather than naming the second template Template:Default, I would suggest making it a subpage like Template:Person/Infobox.