This is most likely an unsatisfactory answer, but it depends on the background and theme. By default, the text must always, of course, be the most visible. If you select a light background, the text will turn to black.
Try this as proof. Right click a desktop icon and drag it over the lighest part of the desktop - this site, for example. The text will become black.
There may be some third part apps or desktop backgrounds that can do it for you, but I know of one.