I've seen this exact advice in the Tango icon theme guidelines several years ago: http://tango.freedesktop.org/Tango_Icon_Theme_Guidelines#Frequent_Mistakes htt

I've seen this exact advice in the Tango icon theme guidelines several years ago: http://tango.freedesktop.org/Tango_Icon_Theme_Guidelines#Frequent_Mistakes http://tango.freedesktop.org/Tango_Icon_Theme_Guidelines#Fre... But i think it only applies for low-contrast backgrounds, like in these examples, for high-contrast backgrounds it doesn't necessarily make scanning harder. It depends on whether multiple distinctive colors are used for the icon itself. Icons without distinctive shapes often only use one colors for the icon itself and another color (or even multiple colors) for the background. I think this complicates scanning much more. Also, removing unnecessary complexity from icons is almost always benefiting. So, yes, if possible, you should remove meaningless background shapes.