Is it possible to set a default desktop background image in Yosemite that'll be used automatically in every Spaces virtual desktop I create? I find that I use spaces a lot, but have always hated brightly coloured and distracting desktop backgrounds. It gets annoying having to go into "Change desktop background" every time I create a new desktop. I've tried removing all the Apple images from the library/desktop pictures folder and just putting a my image in there, but all Mac OS X did was default to its standard Yosemite cliff face image when a new desktop was created. Is there any way to simply replace that image, so that Mac OS X will always use the one of my choice?