Any way to change background?

I’m new to blender and looking to spend a lot of time in the software, but the eternally grey background is seriously bringing me down. Is there any way to change the background to an imported image? Or even just a different color

You can change the viewport colour in the File / User Preferences / Theme settings

You can also add a world background texture in cylces and in the viewport display settings you can enable this to be shown in the viewport
https://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.73/UI