I installed Mint 15 xfce on my little boy's computer yesterday and he's loving it. Unfortunately, the desktop backgrounds he chooses often conflict with the desktop icon's font colour. A quick and simple way of changing the desktop font colours would be hugely useful.
While it isn't as easy as it could be, you can change the font colors and more. Have a look at http://git.xfce.org/xfce/xfdesktop/tree/README#n32
Following that argument, all apps would have to have UI-settings to change the color of the font (or other elements). I'd rather say this is a "bug" or downside of Mint's default theme if it disables the bubble around the desktop items' labels that keeps them readable at all times. Also, this is a typical theming thing: either customize it (in this case: following the readme) or use a theme that looks like you want it. Either way, adding a UI setting for this seems a bit over the top.