To modify the text for icons on the Desktop in Gnome (i.e. Nautilus), you must override them...
nano /home/USERNAME/.gtkrc-2.0 style "desktop-icon" { utilusIconContainer::frame_text = 1 text[NORMAL] = "#000000" NautilusIconContainer::normal_alpha = 128 } class "GtkWidget" style "desktop-icon"
The fram_text needs to be one to set it to black, the IconContainer bit is a semi transparent rounded box... 128 could be 1...